Romans 2:14

2:14 For whenever the Gentiles, who do not have the law, do by nature the things required by the law, these who do not have the law are a law to themselves.

Romans 11:24

11:24 For if you were cut off from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these natural branches be grafted back into their own olive tree?

Romans 16:18

16:18 For these are the kind who do not serve our Lord Christ, but their own appetites. By their smooth talk and flattery they deceive the minds of the naive.