'Allegiance' in the Bible

I am astonished and extremely irritated that you are so quickly shifting your allegiance and deserting Him who called you by the grace of Christ, for a different [even contrary] gospel;

Those who want to make a good impression in public [before the Jews] try to compel you to be circumcised, just so they will escape being persecuted for [faithfulness to] the cross of Christ.

and then have fallen away—it is impossible to bring them back again to repentance, since they again nail the Son of God on the cross [for as far as they are concerned, they are treating the death of Christ as if they were not saved by it], and are holding Him up again to public disgrace.