All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
In principle, in Islamic religion, whoever utters the two testimonies of faith, which is to say: "Ash-Hadu Allaa Ilaaha
The question to be asked here is: What prevents you from sincerely embracing Islam and correcting your intention? Islam is the true religion which Allaah chose for the people and by which He abrogated all previous religions. Whoever embraces Islam and abides by its legislation will be happy in this life and in the Hereafter, and whoever chooses a religion other than Islam, he will be unhappy forever. Allaah Says (what means): {And whoever desires other than Islam as religion – never will it be accepted from him, and he, in the Hereafter, will be among the losers.}[Quran 3:85].
Therefore, we advise you to correct your intention and sincerely embrace Islam. We are sure that if you read about Islam with objectiveness and sincerely seek the truth, you will undoubtedly conclude that it is the religion you should be upon. By doing so, you will achieve two benefits, the benefit of sincerely embracing Islam and the benefit of staying with this woman whom you love, and Allaah may also make her your wife in
For more benefit on an introduction to Islam, please refer to Fataawa (plural of Fatwa) 88906, 88151, 86091 and 81979.
It should be noted that if you know that you are not a Muslim, then you are not permitted to have sexual intercourse with this woman, and she is not permitted to allow you enjoy her if she knows the reality of your faith. However, the matter is easy, if you sincerely embrace Islam, then you may renew the marriage contract in a correct way. For more benefit, please refer to Fatwa 90497.
However, continuing to deceive her is unacceptable; neither religion nor sound mind accept such behaviour, and it is not the conduct of honourable and dignified people with real manhood. You either keep her as we mentioned or divorce her.
Allaah Knows best.