Romans 1:19-20

19They should understand what God is like, because God himself has shown it to them clearly.

20Ever since God made the world, he has been showing people clearly about himself. We cannot see God. But the things that he has made show us clearly what he is like. We can understand his great power that continues for ever. We can know that he is the true God. So there is no reason for anyone to say, ‘We could not know about God.’