Allah states that He alone increases the provisions for whom He wills and decreases it for whom He wills, according to His wisdom and perfect justice. So, when the disbelievers rejoice with the life of the present world that was given to them, they do not know that they are being tested and tried. Allah said in other Ayat,
{Do they think that in wealth and children with which We enlarge them. We hasten unto them with good things. Nay, but they perceive not.} [23:55-56]
Allah belittled the life of the present world in comparison to what He has prepared for His believing servants in the Hereafter,
{whereas the life of this world compared to the Hereafter is but a brief passing enjoyment.}

Allah said in other Ayat,
{Say: "Short is the enjoyment of this world. The Hereafter is (far) better for him who has Taqwa, and you shall not be dealt with unjustly even equal to the amount of a Fatila."} [4:77]
and,
{Nay, you prefer the life of this world, although the Hereafter is better and more lasting.} [87:16-17]
Imam Ahmad recorded that Al-Mustawrid, from Bani Fihr, said that the Messenger of Allah said,
"The life of the present world, compared to the Hereafter, is just like when one of you inserts his finger in the sea, so let him contemplate how much of it will it carry."