A lot of Nazis claimed to be Christians.

Matthew 7:15-20 ESV

[15] “Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves. [16] You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? [17] So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. [18] A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. [19] Every tree that does not bear good fruit is cut down and thrown into the fire. [20] Thus you will recognize them by their fruits.

Matthew 7:21-23 ESV

[21] “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. [22] On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ [23] And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’

Romans 11:13-18 ESV

[13] Now I am speaking to you Gentiles. Inasmuch then as I am an apostle to the Gentiles, I magnify my ministry [14] in order somehow to make my fellow Jews jealous, and thus save some of them. [15] For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? [16] If the dough offered as firstfruits is holy, so is the whole lump, and if the root is holy, so are the branches. [17] But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree, [18] do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you.