You appear to have no understanding of this important teaching, so you misrepresent events and passages from the Bible in this regard.
Study first, then come back and we can discuss it. Right now, you're ignorant on the subject. After you're up to speed, I'll be glad to talk with you about it.
That's because I don't feel it is Biblical. So I have no need to understand it.
John 13 34"A new command I give you: Love one another. As I have loved you, so you must love one another. 35By this all men will know that you are my disciples, if you love one another."
Mark 2:17 On hearing this, Jesus said to them, "It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners."
11But 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.
1: She is not a brother. The Greek is masculine(adelphos).
2: She does not fit the parameters of sexually immoral or a drunkard.