1:25: They exchanged the truth of God for a lie, and worshipped and served the creation rather than the Creator . . . for this reason God handed them over . . .
1:28: As they did not see fit to take cognizance of God, God handed them over . . .
These verses show that the prior, non-moral but religious or theological, fall consisted in a rejection of the knowledge of God, an idolatrous turning from the Creator to the creature. This is what the main passage, 1:18-23, says; and this (in Paul’s view) is the fall, not the consequence of it. Man was surrounded by the handiwork of God, his infinitely beneficent Creator, who established him as lord over all his surroundings. But having tasted dominion he sought to be free even of God, and to extend his lordship upwards as well as outwards. He thus refused to glorify God as his Lord, and to give thanks to Him as the giver of all good things. This inordinate pride, the perversion of a lordship that God himself had created for man, was accompanied by the loss of man’s knowledge of God, and idolatry; that is, man’s subordination to the creatures he should have ruled.
—C. K. Barrett, From First Adam to Last: A Study in Pauline Theology, 19