The Necessity of Church Discipline.
A case of incest:
Related Commentaries of 1 Corinthians 5:1
1 Corinthians 5:1-2
1 It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.
2 And ye are puffed up, and have not rather mourned, that he that hath done this deed might be taken away from among you.