Dear …
Please allow me to apologize for all the pain I caused you and your children. I know that my affair with your __(husband/wife)__ __(length of time)__ ago caused unimaginable hurt and suffering for you and I am truly sorry for my indiscretions.
It was wrong for me to allow myself to get involved with __(Name)__. I know that now. At the time, however, all I could see were stars in my eyes. I was blinded by the love I felt for __(him/her)__ and wasn’t thinking clearly. Now, the emotions of my heart are that of remorse and regret.
Back in __(year)__, I had a spiritual awaking that opened my eyes to my adulterous ways, giving me reason to immediately end the affair with __(Name)__. Since then, I have grown spiritually, which has enabled me to now come forth and humbly ask you for forgiveness. I realize that this letter may not be well-received and may even come across to you as insincere; a mere means to clear my conscience. But please, let me assure you that this gesture comes from the very depths of my heart and is completely genuine. I am a changed __(woman/man)__ now and see things differently.
If I could turn back the pages of time, I would do that. It is with the deepest remorse that I look upon all the grief this infidelity caused you and your family. I understand how much you all must hate me for what happened and I don’t blame you. I never meant to cause such trouble in your lives and I’m genuinely sorry for the terrible mistake I made.
Perhaps one day you will find it in your heart to forgive me for all the heartache I have caused. Perhaps one day I will be able to forgive myself.
Sincerely,