"Again, you have heard that it was said to the people long ago, 'Do not break your oath, but keep the oaths you have made to the Lord.'
But I tell you, Do not swear at all: either by heaven, for it is God's throne;
or by the earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King.
And do not swear by your head, for you cannot make even one hair white or black.
Simply let your 'Yes' be 'Yes,' and your 'No,' 'No'; anything beyond this comes from the evil one.An Eye for an Eye
Matthew Chapter 5: Verses 33 - 37
I have written you in my letter not to associate with sexually immoral people,
not at all meaning the people of this world who are immoral, or the greedy and swindlers, or idolaters. In that case you would have to leave this world.
But now I am writing you that you must not associate with anyone who calls himself a brother but is sexually immoral or greedy, an idolater or a slanderer, a drunkard or a swindler. With such a man do not even eat.
What business is it of mine to judge those outside the church? Are you not to judge those inside?
God will judge those outside. "Expel the wicked man from among you."
1 Corinthians Chapter 5: Verses 9 - 13