Marriage should be honored by all, and the marriage bed kept pure, for God will judge the adulterer and all the sexually immoral.

-Hebrews 13:4, NIV

Which is the biggest marital sin that one can commit according to the Bible?

Adultery.

Cheaters–and sometimes, even well-meaning pastors–sometimes treat adultery as a side problem to marriage troubles. This is not a biblical stance to this sin.

Adultery is a real problem when present in a marriage.

A godly pastor understands it is THE marriage problem!

The faithful spouse is not overreaching when he or she insists this is the most important problem to address in the marriage. They are having the mind of Christ when they do so.

Now, the faithful spouse can choose to move on from a cheater without shame per Jesus’ own words (see Matthew 19:9). However, a faithful spouse extending mercy in staying in the marriage ought to be supported by a pastor who grasps this basic stance regarding adultery.

Adultery is very serious. God names it as the only marital sin in Hebrews 13:4 that comes with His judgment. We need to take it just as seriously if we are to have the mind of God.