In this YouTube video, NT Wright has a very interesting section (@12:00 point) in which he identifies Paul’s clear teaching that mankind is made in the image of God:

In every city that Paul visited, he first went to the Jewish places of worship. The Gentiles he ended up proselytizing where those who were “God fearers”, Gentiles studying to convert to Judaism. In Athens, Paul extends his proselytization to the marketplace, possibly because Athens was the premier think-tank of his day. Paul spent his time debating an entire different class of people than his previous ministries. He debated the pagan philosophers, as explained by the video.

Paul enters the city and finds a frightful number of idols. He then explains to the Athenians that they are too superstitious and he was there to explain to them the true God. This speech is very important because in it Paul contrasts the created idols with the true images of God: human beings.

Act 17:27 so that they should seek the Lord, in the hope that they might grope for Him and find Him, though He is not far from each one of us;
Act 17:28 for in Him we live and move and have our being, as also some of your own poets have said, ‘For we are also His offspring.’
Act 17:29 Therefore, since we are the offspring of God, we ought not to think that the Divine Nature is like gold or silver or stone, something shaped by art and man’s devising.

In verse 29 Paul talks about static materials like stone or gold. Paul then talks about the shape of the idols “man’s devising”. He contrasts that to the living, breathing God of the Bible. How does he do this? In verse 28, he explains that we are the truth image of God and we are living and breathing. Paul argues we are like God because we live and breathe. We live dynamically. Our shape is not devised, but purposefully the image of God. God is shown through us, not the pagan images.