I have a question that requires me to go outside of the current congregation where I am a member.
If there is a member who is in an unscriptural marriage, which I do have personal knowledge of, and who is being allowed to preach and teach in worship service, should I remain a member there?
I have approached this member in the past and he absolutely refuses to accept that his marriage is wrong. He was married to another person several years ago, and I knew them both. He committed adultery in that marriage and it ultimately ended in divorce.
Then his current wife was baptized into Christ and they married afterward.
The other members in this congregation have not known this individual long so they don’t know the history.
Please understand that handling such situations rarely go well. There will be hard feelings because many people would rather ignore problems than deal with them. It is the person who points out the problem who is usually blamed (e.g. Moses was blamed for Korah and his followers' deaths during their rebellion (Numbers 16:41-42)).
As it currently stands, it is your word against the brother. Thus, you need to gather evidence that his prior marriage ended because of his adultery. Usually, you won't find that in modern-day divorce records. It might require getting a statement from his former wife.
Once the evidence is gathered, ask two brothers to join you in speaking with him about his situation. The purpose is to document what is the problem, along with trying to convince the brother that he needs to repent of his sin (see Withdraw Yourselves). If this meeting does not go well, then you and the brothers you had to join you need to bring the issue up with the entire congregation.
Only if it is clear that the brother is in sin and the congregation chooses not to do anything that you would need to then look for another congregation to worship with.
Thank you for this very sound guidance. Please pray for me in this difficult situation.