Skeptics ask: Was the Law given by Yahweh perfect (Psalm 19:7), or wasn't it (Hebrews 8:6-8)?

The law is perfect indeed, but the contextual issue for David is that the law is without blemish in and of itself. The contextual issue for Hebrews is that we now have a "better covenant, which was established upon better promises."

The Greek behind better is kreitton, meaning stronger, nobler, or better (Hebrews 1:4 "Being made so much better than the angels, as he hath by inheritance obtained a more excellent name than they.").

Psalms refers to the law. Hebrews refers to the covenant. There is a difference between the law and an agreement to follow the law. One is the terms of the covenant; the other is the covenant itself. The objection ignores this fundamental covenantal difference.

Skeptics ask whether the Law given by Yahweh was perfect (Psalm 19:7) or if it was flawed and needed replacement (Hebrews 8:6-8). This objection fails to grasp fundamental covenantal issues. The law is perfect indeed, but the contextual issue for David in Psalms is that the law is without blemish in and of itself. The contextual issue for the author of Hebrews is that believers now have a "better covenant, which was established upon better promises."

The Greek word behind "better" in Hebrews is kreitton, meaning stronger, nobler, or better (as in Hebrews 1:4). Psalms refers to the law, whereas Hebrews refers to the covenant. There is a strict difference between the law itself and an agreement to follow the law. One represents the terms of the covenant, while the other represents the covenant agreement itself. The skeptical objection entirely ignores this theological difference.

Problem: The psalmist declared that the “law of the Lord is perfect” (Ps. 19:7). It reflects the very character of God (cf. Lev. 11:45). Yet the writer of Hebrews insists that “the law made nothing perfect” (7:19), and thus God brought in a “better covenant” (v. 22). This, he contends, would not have been necessary “if that first covenant had been faultless” (Heb. 8:7). So, who is right? Is the law perfect or imperfect?

Solution: The law was perfect in its nature, but imperfect in its results. It was a perfect expression of God’s righteousness, but an imperfect means of making man righteous. Of course, that is not the fault of the law itself or the purpose for which God gave it. For the law was never given to redeem sinners (Titus 3:5–6; Rom. 4:5), but to reveal sin. As a standard and means of revealing sin, the law was an impeccable norm and teacher. But it was only “our tutor to bring us to Christ, that we might be justified by faith” (Gal. 3:24). Like a mirror, the law was intended to reveal our imperfections as we look into it; but it, no more than the mirror, was intended to correct our imperfections. So the law is perfect in itself, as a rule and revealer of sin, but it is imperfect as a means of empowering us to overcome sin.