Acts 17: 29 “Therefore since we are God’s offspring, we should not think that the divine being is like gold or silver or stone—an image made by human design and skill. 30 In the past God overlooked such ignorance, but now he commands all people everywhere to repent. 31 For he has set a day when he will judge the world with justice by the man he has appointed. He has given proof of this to everyone by raising him from the dead.”
Paul is teaching that God overlooked the worship of Idols in the past, because of the ignorance of Pagans. But from now on (after Jesus' coming), God will judge people, because he gives proof of who God is; The resurrection. The resurrection is the mark between ignorance and knowledge about God.
Now read Romans 1:
20 For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.
Here, Paul is teaching that ignorance of God cannot possibly happen, since God's qualities are known from the beginning of the creation, therefore, all Idolaters are guilty and they will be condemned, no forgiveness offered for them whatsoever.
Two counts of Contradiction:
1/ Knowledge of God came since the creation (Romans 1), VS Knowledge of God came only after the resurrection (Acts 17).
2/ God overlooked Idolatry before Christ (Acts 17) VS God punished Ancient Idolaters (Romans 1).