I need help. I am a young man who loves God. There is a woman I love. She is younger than I. She knows that I am in love with her and she with me. We both have this fear that since we love God we should not act like people who do not know God. We have never been together. We use cell phones to talk even though she is in my church. There was a pastor who told me that I must give up on her because God wanted to use me and she will be unfaithful to me. It is hard to just give up on her. I love her and not just love, but i see her as my wife. Now I have this fear. What must I do? I have been praying that she is a kind of woman I want.
Does this church leader actually have a reason why he thinks the girl you are interested in would be unfaithful? If he is claiming that God told him, then he is lying. God does not speak directly to people as He did in the past. "God, who at various times and in various ways spoke in time past to the fathers by the prophets, has in these last days spoken to us by His Son, whom He has appointed heir of all things, through whom also He made the worlds" (Hebrews 1:1-2). The days of direct revelation are over. "Love never fails. But whether there are prophecies, they will fail; whether there are tongues, they will cease; whether there is knowledge, it will vanish away. For we know in part and we prophesy in part. But when that which is perfect has come, then that which is in part will be done away" (I Corinthians 13:8-10). The "perfect" here is referring to the law of liberty (James 1:25). Now that God has completed His revelation, He is tells us all we need to know through the Scriptures (II Peter 1:2-4; II Timothy 3:16-17; Jude 3).
I suspect that this man just likes to run other people's lives, even though that is a violation of God's teachings. If you love this woman, then get to know her and if you both want to marry, do so.
Meanwhile, I suggest finding a church that follows the Bible instead of the whims of men.