'One' in the Bible

So now I urge you, dear lady—not as if I were writing you a new command, but one we have had from the beginning—that we love one another.

Anyone who does not remain in Christ’s teaching but goes beyond it, does not have God. The one who remains in that teaching, this one has both the Father and the Son.

for the one who says, “Welcome,” to him shares in his evil works.