Is it necessary to renew the marriage contract after repentance from apostasy by reviling God, knowing that the marriage was initially concluded with a guardian and witnesses at Al-Azhar, then at the church, then apostasy occurred and the couple were not praying, then they repented?

We believe that the marriage remains valid as long as the initial contract fulfilled its conditions, and the fact that the man embraced Islam to marry you does not invalidate its صحيح. As for apostasy (riddah), the majority of scholars hold that it nullifies the marriage contract. However, the Shafi'is and Hanbalis (in one narration) are of the view that the separation (furqah) is contingent upon the completion of the waiting period (iddah). If the wife repents before the iddah expires, the marriage remains valid. Some scholars, citing the opinions of Ibn al-Qayyim, Ibn Uthaymeen, and Shaykh al-Islam Ibn Taymiyyah, are of the opinion that the marriage remains valid if the wife returns to Islam, even if a long time has passed.

Therefore, according to this view, your marriage remains valid. However, to avoid any doubt, you may renew the contract in the presence of your guardian (wali) and two witnesses. Know that Allah accepts the sincere repentance of a servant, no matter how great their sin, and He loves those who repent and transforms their bad deeds into good ones. Repentance involves abandoning the sin, regretting it, resolving not to return to it, restoring rights (if any), alongside maintaining discretion and increasing good deeds. For the one who repents from a sin is like one who has no sin. So, rejoice, turn to your Lord, and have a good opinion of Him.