How can a divorced man deal with his ex-wife whom Satan tempts him with, after he committed acts against God with her and repented from them?

We do not know the exact situation the questioner is referring to. If he had intercourse with his revocably divorced wife during her 'iddah (waiting period), scholars have differed on whether this act constitutes a reconciliation or not. However, if he had intercourse with her after her 'iddah had expired, then this is an act of zina (fornication/adultery) for which repentance is obligatory. The command of Allah in the Quran should guide his interaction with this woman, as Allah Almighty says: {And live with them in kindness. For if you dislike them - perhaps you dislike a thing and Allah makes therein much good} (An-Nisa 4:19).