If you abide in me, and my words abide in you, ask whatever you will, and it shall be done for you. Jn 15.7. Sister, if you want to marry a Christian, then you have to be baptized first. We are all born of sin. Baptism is done so as to cleanse our sins, and the sins committed by our first fore parents (Adam and Eve) and also you receive the Holy Spirit as an invitation to Christianity. For more details on this please go to the Church where your lover belongs and ask the Parish Priest. He can explain it you very clearly.