All men live in order that they might know God.
You cannot find a man anywhere, however uncivilized or wild, who is without some idea of religion. This is because we have all been created to know the majesty of our Creator and, in knowing it, to think more highly of it that anything else. We are to honor it with all awe, love and reverence.
Unbelievers seek only to wipe out all memory of this sense of God which is planted in their hearts. Leaving them aside, we who claim to have a personal religion must call to mind that this present life will not last and will soon be over. We should spend it thinking about immortality.
Now, eternal and immortal life can be found nowhere except in God. It follows, then, that the main care and concern of our life should be to seek God. We should long for Him with all the affection of our hearts, and not find rest and peace anywhere except in Him alone.
John Calvin, Truth For All Time, 1537