That is Genesis 11, for those who are interested to check up on it. A better translation for the verse in 1 Cor. But which translation isn't really that important and different.
Every text has a context and that is always important to take into consideration.
But it really takes more to produce a contradiction. But though this is not said every time, it is obviously only a guidance, let alone a clear one, to those who are willing to be guided. To those who reject it it means confusion. Those who doubt are the ones that are confused. And that is basically what Paul is talking about too in the verse you quote.