Man seeks nature as his first end, virtue as his second end, and narrow happiness as his third and last end. These things together measure what I in my book call “true” happiness.
Notice that God impinges on all three of these quests.
It is human nature to love other people. But if one has faith, then he knows that the branches are connected not only to each other but to the vine, as well. Grace-infused love endures, is forever, and wills to neighbor the highest possible good.
Virtue here is used in the broader sense which includes wisdom as the 7th (or 8th if we count temperance) and highest virtue. But, says St. Thomas:
This [sacred] doctrine is wisdom above all human wisdom; not merely in any one order, but absolutely. For since it is the part of a wise man to arrange and to judge, and since lesser matters should be judged in the light of some higher principle, he is said to be wise in any one order who considers the highest principle in that order… Therefore he who considers absolutely the highest cause of the whole universe, namely God, is most of all called wise. Hence wisdom is said to be the knowledge of divine things. (ST, I, 1, 6)
[H]e who knows the cause that is simply the highest, which is God, is said to be wise simply, because he is able to judge and set in order all things according to Divine rules. (II-II, 45, 1)
[T]here can be no perfect and universal judgment that is not based on the first causes. (II-I, 57, 2)
No one can be truly wise who does not acknowledge God as the first cause of creation, redemption, and sanctification.
Nor innocent, as the most obvious connection between religion and morality is fear of punishment in the next life. A religious man seeks to be innocent before God who knows secret thoughts, not just other people whom he may be able to deceive.
Finally, narrow happiness for which a godly man can hope consists in having God as the most beautiful thing one can possess or the whole of all truth or whatever he temperamentally prefers. Temporal goods pale in comparison.