I am facing a heartbreaking situation right now. I met my fiancee two years ago and I happily discovered we have the same vision: being totally consecrated to the Lord. She is a very good and spiritual person to me and we understand each other very well. When we met, we were in our early twenties.
She decided we should keep our relationship a secret, but I refused and urged her to let her family know about it.† She told me she knew her family would not be supportive since she hasn't graduated from college. I kept pushing her, and she finally informed her family, who did not even think twice before rejecting her decision. Her parents are not Christians, by the way.
I told her to go ahead and finish her education and and that way we will have her parents blessing. She said she is not even willing to finish her school. She wants to serve the Lord and have time to work for the ministry.†She already has a job and she cannot afford to do three things at a time (school, job,†and ministry). She decided she will opt for the ministry and then later go back to school.†
When we met, I was in a moment of weakness, but the Lord used her to strengthen me and led in my heart to start the ministry through which we shall be able to consecrate ourselves. We started and we've been growing little by little. But we're facing a serious problem right now: some people think we are committing sin of fornication, and besides that we've been really struggling with it: we haven't completely fallen yet, but we are bent over. I cannot struggle any longer. We've decided to go ahead and get married, but her parents are still refusing to bless the wedding.† They said they are steadfast and nothing will change their minds. Her pastor also told her not to marry me because I am from a different church, and I may take her away. We want to make the decision of getting married, but she is intimidated by the fact that her parents will not bless the wedding.
I wanted to end the relationship since I'm so tired of it, but if I do, the ministry will fall down. I am in a very tough situation. I cannot sometimes sleep, and it really† pains me a lot. What should we do about this confusing situation?
First, whoever you marry is your decision -- not your parents or anyone else. There is no requirement that parents bless their children's marriages. Instead, God teaches, "Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh" (Genesis 2:24). Prior to marriage, a person leaves his parents. It is nice to know that your parents approve of the person you pick to marry. If your parents have an objection, it should be seriously considered. But it is possible that your parents are wrong.
There are some concerns. The fact that she wanted to hide her relationship with you is not good, even knowing her parents would not approve. This certainly would not gain their approval nor put Christianity in general in a good light.
Your use of the word "ministry" is vague. In the Bible it just means "service," so I don't know what act of service she is involved in. But you make it sound as if she is in a leadership role of some sort. I would like you to consider: All the Members Do Not Have the Same Function and Objections to Biblical Limitations on Woman's Role.
You also mention that fornication is a huge temptation for the two of you and that you've come close in the past. Generally that indicates that you are focused on not having sex, but you are allowing yourself to commit other sins that could lead up to sex. See: What sexual acts should not be committed in a relationship before marriage?
Being of two different denominations or beliefs is also a concern. Right now you've found a way through a common project, but if you see yourself, say a Baptist, and she a Pentecostal, those differences in beliefs will eventually become a problem, especially when you start to have children. What typically happens is that the parents fight over which religion the children should be raised in. As the child grows he gets different answers from mom and dad to his questions. The usual result is that the child grows up to be an atheist. This is one of the reasons denominationalism is wrong. "Now I plead with you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no divisions among you, but that you be perfectly joined together in the same mind and in the same judgment" (I Corinthians 1:10). See: If Christ Built Only One, Where Did They All Come From?
The fact that she is letting outside pressure to cause her to put off marrying you is also not a good sign. What happens when other difficult decisions need to be made in the future? Will she do what is right or follow every wave of doctrine (Ephesians 4:14-15).