I am Muslim from birth but I met a Christian guy who loves me and want to convert because of me. I Am confused and don't know what to do.
Asalaam Aleikum sister,
Without knowing much detail about your situation, it is hard to give specific advice. InshaAllah you will still benefit from our response.
First and foremost, conversion to Islam should be only for Allah (SWT) and not just for the sake of marriage. When a person says the shahadah, he/she should really, truly believe that Allah Subhanah wa' ta 'ala is the one true Creator, that He has no partners, and that Muhammad (SAW) is the last prophet. The person must also be aware of and willing to take on and work to uphold the five pillars of Islam as well as transform their life to align with Islamic principles. Of course, this does not happen overnight, but a prospective Muslim must be aware and willing to take on these responsibilities. Men and women who were not sincere in converting generally end up denouncing Islam later, not truly practicing, or admitting that they are “just going through the motions for appearances.” It is important to be honest and evaluative in your situation. Does this Christian man truly have interest in Islam? Does he believe in the oneness of Allah and the Prophet Muhammad(SAW)? Does he want to live a Muslim lifestyle? If he is sincere, then introduce him to your local imam or a trusted Muslim brother to guide him in his journey to learn about Islam. InshaAllah, he will truly accept the deen.
Second, if he does sincerely convert, give him some time to learn about Islam. Marriage in Islam is not a light matter. There are very specific responsibilities that a husband has towards his wife and future children inshaAllah. New male converts to Islam have to adjust to the concept of lowering their gaze and the rights his wife will have over him. Some couples complete a nikah ceremony immediately following one spouse’s shahadah, and alhamdulillah it works out. Other couples have to confront many conflicts due to misaligned perceptions of an Islamic marriage and each spouse's responsibilities.
Finally sister, the question that was not addressed is do you want to marry him? If you do not feel strongly for him, then I urge you to minimize contact with this man. All too often, muslimahs sometimes find themselves in compromising situations with non-Muslim men. If you do, please sister, make istakarah about this situation and seek the guidance of a wali or local imam to help this Christian man accept Islam if that his is sincere desire.
I pray that you may only benefit from this response.