I'm not sure what the difference is. Scripture teaches that divorce is valid for those reasons outlined above. This would seem to indicate that remarriage is scripturally sanctioned. Of course if a person divorces for non-scriptural reasons, then I would say that remarriage is adultery.
I don't want to presume something and I don't want to try and explain disobedience to the Lord. The Lord is clear about the divorce issue. Nowhere does he sanction and bless the re-marriage.
I thank God that He forgave a Wretch like me. Jesus and Paul tell us that marriage can be compared to Christ and His church(us, the believer). Have you ever known anyone to backslide from his first love? I have. And, I've seen how miserable they treat the Lord in all of their sin. Jesus still loves them and prays for them to return to Him. When the backslider comes to his senses, repents and asks the Lord to take him back again, does he find that Jesus has divorced him and turns His back on him?
We have been instructed to be likewise to our errant spouses.