Let's take a closer look at the story of the "sheep and the goats" and address some interpretations offered by various scholars and critics.

The first comes of the part which says, "And the King shall answer and say unto them, Verily I say unto you, Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me." (25:40) Modern ideas have demanded that the "brethren" in question consist of any poor or oppressed person, and given the interpretation that helping such as these is the ultra-qualifier which makes the heavenly grade.

The second is broader and related: If people are being judged by what they do for the brethren, isn't this salvation by works -- and what happens to salvation by faith? Does this mean our religious beliefs make no difference?

Under the Semitic Totality paradigm, thoughts that result in no action are vain. When Paul encourages believers to "work out your own salvation with fear and trembling," (Phil. 2:12) he is calling us to synergistically cooperate with God's grace. We participate in His righteousness; what is needed is for us to cultivate this and live consistently with it.

Note the qualification of Romans 3:20: "by the deeds of the law there shall no flesh be justified in his sight." Romans 2:5-10 does mean that a person who persists in good deeds will be granted eternal life, but as Romans 3 goes on to show, no one can live a life in accordance with the commandments of God apart from His grace; faithful obedience is only possible through communion with Christ.

The passages in Matthew, then, show no more than that those who had faith actually lived it out, as we would expect. As Orthodox theology emphasizes:
> It is a continual seeking after God, accompanied by a persistent doing of what is good, that reflects a heart transformed by grace.

It is obvious, then, that a living and real faith—one that works through love—is what saves, as is made clear by Ephesians 2:8-9: "For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast."

Who are the "brethren"? The poor, the sick?
No --
> Matthew 12:48 But he answered and said unto him that told him, Who is my mother? and who are my brethren? And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren! For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.

The poor, the sick, and so on is not a group in a one to one identity with those who do God's will. Who are those who do God's will? In the above, it is clearly the disciples of Jesus. Matthew 25:31-46 is all about judgment based on how one treated the disciples of Christ.

The passage needs to be read in light of these earlier ones:
> Matthew 10:14-15 And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet. Verily I say unto you, It shall be more tolerable for the land of Sodom and Gomorrha in the day of judgment, than for that city.
> Matthew 10:40-42 He that receiveth you receiveth me, and he that receiveth me receiveth him that sent me. He that receiveth a prophet in the name of a prophet shall receive a prophet's reward; and he that receiveth a righteous man in the name of a righteous man shall receive a righteous man's reward. And whosoever shall give to drink unto one of these little ones a cup of cold water only in the name of a disciple, verily I say unto you, he shall in no wise lose his reward.

A disciple traveling to and fro with the word in the ancient world is very likely to be in the condition of those described in 25:31-46 -- sick, poorly clothed, and as Jesus predicts, in prison.

What about the atheist who treats Christians nicely? Does he get to heaven, according to this?
If this passage were taken in strict isolation, and meant to be taken that way, and written in the context of an individualist society like ours, one might have a case for that odd individual getting a golden ticket, but it's not so simple.

The parable of the sheep and the goats draws upon a certain paradigm found within Judaism of Jesus' day, which held that the nations (cf. 25:32) would be judged based upon how they treated Israel (4 Ezra 7:37), and the related concept encouraging repressed minorities that God will judge the world based on their treatment of them. In holding this it was never assumed that this was the sole and exclusive basis for judgment. The specific matter of treatment of Israel was isolated to make a point of its importance in context (and here, the context is the end of the age of the law and the beginning of the age of the Messiah -- when the Gospel message would be brought to the Gentile world as a whole).

Moreover, the identification of Jesus with the disciples draws us even closer to the "faith" position. One's response to the disciple is the same as one's response to Jesus, and in a collectivist society, one would not assist a member of a divergent party in the way described unless one accepted and agreed with their message. As Malina and Rohrbaugh note, this parable draws the classic ancient distinction between "ingroup" and "outgroup". There would be no such thing as a "friendly pagan or atheist" who would have sympathy for the Christian.

In short, it would be illegitimate to take this passage in isolation and suppose that it gives hope for salvation outside of the atoning death of Christ.

The Bible’s teaching on the reality of eternal punishment for unbelievers has perhaps “made” more atheists than any other teaching of Scripture. After expressing that he did not “believe one can grant either superlative wisdom or the superlative goodness of Christ as depicted in the Gospels,” popular early-20th-century agnostic Bertrand Russell indicated that he was not concerned about what other people said about Christ, but “with Christ as He appears in the Gospels.”1 How so? In his widely distributed pamphlet “Why I Am Not a Christian,” Russell argued, “There is one very serious defect in Christ’s moral character, and that is that He believed in hell. I do not myself feel that any person who is really profoundly humane can believe in everlasting punishment. Christ certainly as depicted in the Gospel did believe in everlasting punishment.”2
Many Christians foolishly and hypocritically avoid the Bible’s teaching on hell, but refer regularly to Scripture’s allusion to heaven. Yet, as Russell and many other critics of Christ are very well aware, according to Jesus and the Bible writers, “eternal punishment” is just as much a reality as “eternal life.” After explaining to His disciples how God will separate the righteous from the wicked at the Judgment (Matthew 25:31-45), Jesus concluded by telling them that the wicked “shall go away into eternal punishment: but the righteous into eternal life” (25:46, ASV).3 Earlier He stated that the wicked will be sent away “into the everlasting fire prepared for the devil and his angels” (Matthew 25:41). Hell’s fire “shall never be quenched” (Mark 9:43), the figurative “worm” that eats on the flesh of hell’s inhabitants “does not die” (Mark 9:48), and the wicked who find themselves in hell (due to their rejection of God’s gracious gift of salvation through Christ) “shall suffer the punishment of eternal destruction” (2 Thessalonians 1:9, RSV). As it was in Sodom, when God “rained fire and brimstone from heaven and destroyed them all, even so will it be in the day when the Son of Man is revealed” (Luke 17:29-30). Thus, as Jesus taught, “My friends, do not be afraid of those who kill the body, and after that have no more that they can do. But I will show you whom you should fear: Fear Him who, after He has killed, has power to cast into hell; yes, I say to you, fear Him!” (Luke 12:4-5).

Bertrand Russell accused Jesus’ preaching to be full of “vindictive fury against those people who would not listen to His [Jesus’] preaching.” “You do not,” he contrasted, “find that attitude in Socrates. You find him quite bland and urbane towards the people who would not listen to him; and it is, to my mind, far more worthy of a sage to take that line than to take the line of indignation.” He added:

I really do not think that a person with a proper degree of kindliness in his nature would have put fears and terrors of that sort into the world…. I must say that I think all this doctrine, that hell-fire is a punishment for sin, is a doctrine of cruelty. It is a doctrine that put cruelty into the world and gave the world generations of cruel torture; and the Christ of the Gospels, if you could take Him as His chroniclers represent Him, would certainly have to be considered partly responsible for that.

So there you have it: how can people believe and accept the message of the chroniclers of Christ (i.e., the Gospel writers), when such accounts are full of hell-fire-and-brimstone preaching?

Consider four reasons why Jesus’ and the Bible’s teachings on hell logically should not make anyone an atheist. First, Bertrand Russell stated that he did not “feel” that any “humane” person can believe in eternal punishment, and since Christ did, then He had a “defect” in His “moral” character. Yet, truth, objectivity, and logical argumentation are not based upon people’s feelings. Atheists cannot logically condemn the Bible’s teaching about hell as objectively “inhumane” and “immoral,” while simultaneously believing that human beings arose by chance from rocks and rodents over billions of years. If an eternal, supernatural Creator does not exist, then objective4 goodness and wickedness, justice and cruelty cannot logically exist. Actual good and evil, fairness and unfairness can only exist if there is some real, objective point of reference—“some objective standard…which is other than the particular moral code and which has an obligatory character which can be recognized.”5 Indeed, the best that atheists can “argue” about the biblical teaching of hell is that they “feel” like it is “immoral,” but they cannot actually prove such.
Second, atheists and agnostics also fail in their assessment of hell because they fail to grasp what the Bible teaches about the reality, offensiveness, and severity of sin. This failure should come as no surprise because a person cannot have a proper view of sin without having a proper view of God and the Bible. Once a person comes to know that God exists and the Bible is His Word,6 he then learns that there are no “white lies,” innocent “alternative lifestyles,” or mere “affairs.” There is only Truth or lies. There is only God’s infinite right way versus all of the prideful ways of man. There is only pure holiness versus repulsive unholiness. There is only light and darkness. And, since “God is light and in Him is no darkness at all” (1 John 1:5), His innately pure and holy nature will not allow Him to tolerate lawlessness (Habakkuk 1:13; Isaiah 59:1-2; 1 John 3:4).

Third, God’s perfect justice demands punishment for wrongdoing. The Bible reveals that God is 100% just. There is nothing unfair about Him. “Righteousness and justice are the foundation of Your throne,” exclaimed the psalmist (89:14). “All His ways are justice, a God of truth and without injustice; righteous and upright is He” (Deuteronomy 32:4). A just judge is one who shows no partiality (Deuteronomy 1:17), and God “shows no partiality nor takes a bribe” (Deuteronomy 10:17). A corrupt judge allows the guilty to go unpunished, while a just judge pronounces righteous judgment upon lawbreakers. “[H]e who does wrong will be repaid for what he has done, and there is no partiality” (Colossians 3:25). The guilty cannot “buy” their way out of punishment. They can’t “flirt” their way out of righteous judgment. Similar to how citizens of an earthly kingdom rightly rejoice at the pronouncement of punishment for the wicked, humanity should rejoice that we have a just Judge who also punishes evildoers.

“But wait a minute! A just judge wouldn’t punish people forever!” Says who? Says the sinner who has a shallow, flippant view of the wretchedness of sin and the holiness of God? Says the sinner who did the crime but doesn’t like the time? Says the person who is not perfectly impartial? Says the person who knows virtually nothing compared to the omniscience of God? What’s more, aren’t just and fair sentences and punishments (even in the physical realm) often much, much longer than the amount of time the crime actually took to commit? A man can murder an innocent person in only one second and yet justly spend the next 1.5 billion seconds (or 50 years) in prison. Certainly the thought of being punished forever and ever is a sobering, scary thought, but in truth, only the omniscient, infinitely wise, and perfectly just Judge is in a position to decide appropriate punishment for unforgiven sin. In truth, a rejection of God based upon the biblical teaching of hell is a rejection based upon emotion, not evidence.
Fourth and finally, though “all have sinned and fall short of the glory of God” (Romans 3:23), and though all sinners deserve eternal punishment, because of God’s perfect love, no one has to go to hell. God has given us an all-powerful, spiritual lifeline (Romans 1:16). Indeed, “the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord” (Romans 6:23). Some unbelievers love to talk about God’s “vindictive fury,” but they willfully ignore the overall theme of the Bible—“God is love” (1 John 4:8). He doesn’t want anyone to perish (2 Peter 3:9). God “desires all men to be saved” (1 Timothy 2:4). From the moment wretched sin entered the world, God began revealing His answer to the sin problem (Genesis 3:15; 12:1-3). Following thousands of years of promises and prophecies throughout the Old Testament pointing to the ultimate “Lamb of God Who takes away the sin of the world” (John 1:29), “God sent forth His son” to redeem the slaves of sin to become children of God (Galatians 4:4-5). “God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved” (John 3:16-17). Indeed, God is so loving that He not only warned us of the eternal consequences of unforgiven sin,7 but even when we succumbed to sin, God took upon Himself the punishment for our sins, that we might be saved! So why will many people still go to eternal hell? Because they choose to. Because they “trampled the Son of God underfoot, counted the blood of the covenant by which he was [they were] sanctified a common thing, and insulted the Spirit of grace” (Hebrews 10:29).