Knowledge puffs up, but love edifies. And if anyone thinks that he knows anything, he knows nothing yet as he ought to know.
-I Corinthians 8:1b-2, NKJV
Just because a Christian has been married for a long time does not mean said Christian is equipped to properly advise a faithful spouse dealing with a cheater.
An not uncommon problem faithful spouses encounter are Christians who have been married for decades thinking that qualifies them to pontificate on all things married. In particular, these long-married Christians believe their advice given to the faithful spouse is gold, and ergo, it ought to be followed at all costs.
In a word, these long-married Christians are “arrogant!”
Unless you work regularly with the character disordered, have gone through a divorce with a cheater, and/or regularly work with people dealing with cheaters, one’s ability to actually provide good and wise advice for a faithful spouse is limited. It is hard to wisely assess the situation if one is unaware of the true depths of human depravity that faithful spouses encounter on a regular basis in dealing with cheaters.
While I agree with these Christians regarding how the Bible has useful advice for faithful spouses, the problem is in properly handling the text. Being married for decades and even being a Christian for decades does not necessarily qualify a Christian to handle the text properly in regards to situations involving marital infidelity.
In fact, I would argue such a long-married Christian is at a disadvantage to another who has survived infidelity or supported a loved one through a divorce prompted by infidelity. Such a Christian has more related experience with which to empathize with a fellow brother or sister going through such an experience. That is an advantage as such empathy makes it less likely the later Christian will beat the faithful spouse over the head with marriage “knowledge.”
And I want to be clear: I think it is wonderful to see Christian marriages last a long time. I am grateful that both sets of my grandparents had long and fulfilling marriages. My problem is not with Christians who are long-married.
My issue is with the arrogant subset of long-married Christians who believe they have knowledge–which they think they must impart–when they do not in the matter of an infidelity-ravaged marriage.