"O come, let us sing unto the Lord" [Psalm 95:1]. He calls us to a great banquet of joy, not one of this world, but in the Lord. For if there were not in this life a wicked joy which is to be distinguished from a righteous joy, it would be enough to say, "Come, let us rejoice;" but he has briefly distinguished it. What is it to rejoice aright? To rejoice in the Lord. You should piously joy in the Lord, if you dost wish safely to trample upon the world. But what is the word, "Come"? Whence does He call them to come, with whom he wishes to rejoice in the Lord; except that, while they are afar, they may by coming draw nearer, by drawing nearer they may approach, and by approaching rejoice? But whence are they afar? Can a man be locally distant from Him who is everywhere?...It is not by place, but by being unlike Him, that a man is afar from God. What is to be unlike Him? It means, a bad life, bad habits; for if by good habits we approach God, by bad habits we recede from God....If therefore by unlikeness we recede from God, by likeness we approach unto God. What likeness? That after which we were created, which by sinning we had corrupted in ourselves, which we have received again through the remission of sins, which is renewed in us in the mind within, that it may be engraved a second time as if on coin, that is, the image of our God upon our soul, and that we may return to His treasures....
[AD 430] Augustine of Hippo on Psalms 95:1