Let's face facts, not all marriages should be saved. Sometimes the two partner's just aren't compatible and just can't make thinks work. At other times there are real issues such as marriage infidelity, which can be virtually impossible to move past.
Listen to your gut feeling
If you or your spouse has been unfaithful but you both feel that there is still something in the relationship worth saving, it's time for a gut check. Don't think that the road to save your marriage will be smooth or short. You had better prepare for a rough ride, and it's going to have a much better chance of working if you enlist the help of a professional counselor to help clear the path, as much as possible.
Here are a few things to keep in mind:
1. If the person who committed the adultery is a serial cheater, why stay at all? Come on,who are you kidding? No matter how much you may love them, they are flawed. They aren't ever going to change they are just going to make your life miserable at best, and at worst they'll bring some nasty disease home and clear out your bank account. Leave.
100% Commitment is Important
If this was a one time lapse in judgment, and let's be honest, in the right circumstances any of us could have one, than you might have a chance but only if the offending party is truly sorry and will, or already has, stopped seeing the other person. If they won't commit 100% to making things work, it won't work. Again, it's best to leave.
2. As hard as it may be to face, it might help if the two of you could talk openly about what they found so irresistible in the other person. It's going to hurt, but the reality is that people don't cheat for sex, though that is part of it, they cheat because they get something from the other person that they don't get from their spouse.
Find that Spark in Your Relationship
Sometimes it can be something 'real' like feeling needed or loved. Other times it's not 'real' it's childish, like feeling like they are the only one that matters in the relationship. Finding out what the attraction was might help the two of you recapture something that has been lost in your relationship, something that you may not even have realized was gone.
3. It's very important to the long term health of your relationship that the person who was cheated on can find a way to not throw it up in their partner's face every time there is a fight. And that will be hard. But unless you can truly forgive and forget, it won't work out.
Trust takes forever to repair!
On the other side of the coin, the person who strayed must understand that it can take a lifetime for their partner to really ever trust them again. Sorry, that's just the way it is.
Also, the person who strayed has to own it, period. Now is not the time to blame your spouse and use the classic line: "my wife/husband just doesn't understand me". B.S. You are every bit as guilty, maybe more so, in the failing of your marriage as your spouse. Don't blame your weakness and the fact that you cheated on your partner. You did it, period. Own it and you'll be a better person for it.
Marriage infidelity can be gotten past, but only if the two of you are willing to try, and try hard. Good luck.