Seeing the state of the woman, a young man who was not married and who also was an idol worshiper and an uneducated day laborer, who also lived in the same slum, decided to give her a life. He started living with her and provided all the needs for her and the children. He did not marry any other woman, nor he did have children with this woman.
Several years ago, they have converted from idolatry to Pentecostalism. All of the children are now grown up. He has arranged marriages for all of the children and settled them from his earnings.
A year ago, he started attending our Bible class. After I taught about baptism and the marriage relationship, he opened up about his life and explained his situation. He wants to be saved by accepting Jesus as his Savior and obey the Gospel through water baptism.
Please explain how this should be handled.
Because the woman's husband left her for another woman, she has the right to marry again (Matthew 19:9). The problem is that she and this man have been living together, and I would assume that they have been having sex.
Since baptism is based on repentance (Acts 2:38), then the proper thing would be for this man to marry the woman he has been living with for so long. Since a wedding can take place fairly quickly in most countries, he can then get baptized after he corrects his sinful life. An alternative is that he can temporarily move out until the wedding takes place and be baptized after he moves out.