How do Christians deal with this contradiction from the OT 2D NT?

As others on here have already mentioned, there is no contradiction here. You're taking one set of principles towards a particular group of a particular time, and applying them to a different group in a different time. It makes no sense. YOU are creating the contradition. The Ezekiel verse is addressing JEWS that were part of the old covenant in the time before the messiah. The Galatians scripture is addressing GENTILES that are part of the new covenant living in the time after the messiah. The gentiles were never commanded to be circumcised (even in the OT). God does NOT change, nor has he. However times HAVE changed and there was no messiah when the Ezekiel scripture was addressed. The many of the old laws have been fulfilled by the coming of the prophesied messiah. Perhaps you should actually study the bible in Sunday school instead of quoting it out of context, then claiming that it is a contradiction. Such an action only shows that you don't know what you're talking about.