The Bible is very much clear in addressing the sin of sodomy, which, I believe, no Spirit-led Bible-believing Christian will argue against; but the issue now is: is anal sex sin if it is had in marriage between a husband (man) and his wife (woman)?
Let’s first define what anal sex is. Anal sex is a man putting his penis into the anus. It is taking anus for vagina. This is sodomy! It is sin! This is not natural, and it is not biblical sex. Biblical sex is holy but anal sex is immoral.
God created anus for excreting waste, not for sex. This is sexual immorality. The Bible condemns this.
“If a man has sexual relations with a man as one does with a woman, both of them have done what is detestable. They are to be put to death; their blood will be on their own heads.” (Leviticus 20:13).
“You shall not lie with a male as with a woman; it is an abomination.”( Leviticus 18:22).
“For of this you can be sure: No immoral, impure or greedy person — such a man is an idolater — has any inheritance in the kingdom of Christ and of God.” (Eph. 5:5).
From the above Bible verses it is very clear that God hates sodomy (anal sex).
The simple truth is this: God created vagina for sex while anus is created for faeces. Know that
“Marriage should be honored by all, and the marriage bed kept pure, for God will judge the adulterer and all the sexually immoral.” (Heb. 13:4).
Honour your marriage and keep it pure from all forms of sexual immorality.
Also know that sexually immoral activities give demons access into one’s life. We must know that sexual immorality is one of the greatest weapons Satan is using against humanity today.