I'm a 20 year old girl who's engaged to a man more than 15 years older than me. He is my first boyfriend, and I'm physically and emotionally intimate with him. But I'm afraid of marriage because I have only dated him and no one else. He is a great man who is a believer and he would make a good husband and father. But I'm afraid of committing without having considered other options available to me. I don't know what to do. I love him, and he loves me more, but I feel worried about marriage. I'm happy, but what if I could be happier with someone else?
I met him on a dating site and we began to date since then. We didn't meet each other naturally. I was just a lonely teenager who wanted love and rather than waiting for God to bring a man into my life, I signed up to a dating site, in the hope of finding a man there, which I have. But I don't know if this is what God wants me to do.
Also, my fiance †has a good job. We live comfortably, but I have doubts he can give me the lifestyle that I want in future - having many children and me being a stay-at-home Mom, looking after the home. It would be possible; however, it wouldn't be very easy. I'm not materialistic; however, I do care about the well-being of my future children. He always pays for everything whenever we go places, but we don't have a family yet, so it isn't difficult. It would break my heart if I broke up and he would suffer too, but would it be worth it?†
This has nothing to do with God. This is a young woman questioning her choices after she has made them. The idea that God has just one person in mind for you to marry is false. God tells us through the Scriptures how to pick a good spouse. Whether you follow His advice is up to you.
As it is, you've been ignoring God anyway. You are living with a man you are not married to and having sex with him. "Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God" (I Corinthians 6:9-10).
You also are in love with your imagination. You think there might be someone out there that will make you happier, as if your personal happiness is most important. For that matter, happiness is also something you choose. It isn't something given to you. Happiness is purely a choice that you make to enjoy life as it is. "Not that I speak in regard to need, for I have learned in whatever state I am, to be content: I know how to be abased, and I know how to abound. Everywhere and in all things I have learned both to be full and to be hungry, both to abound and to suffer need. I can do all things through Christ who strengthens me" (Philippians 4:11-13).
Your fears are also imaginary. Sure, lots of things could happen, but rarely are things as bad as you might imagine.
There are always risks in any choice. When you make a decision, you are giving up somethings to gain others. But to make no choice is to gain nothing.
If this man makes a good husband, then marry him, as you should have done before having sex with him.