I would like to develop a relationship with someone, and get married in a few years' time. My problem is that there are three girls I like a lot, and I can't decide!
Don't rush yourself into a decision. Get to know all of them, and develop your friendship with each girl. Friendship is essential, because marriage is a sharing of lives and not just the sharing of the same bed at night. If you find that you cannot relate to a girl as a friend, you shouldn't even think of marrying her. You must be fair, of course, and you should make it clear to each girl that you are not yet ready to commit yourself to any one person. Just as you want to be free to mix with other girls, they would also be free to mix with other boys.
As your friendship develops with each girl, you will probably find after some time that you prefer one more than any of the others. Of course, you could discover that none of the three girls really suit you, or that you like a fourth girl most! At some stage you will tell yourself: "I have met so many girls in my life. Now I want to share my life in a special way with this particular person". Both of you can discuss it, and if she thinks the same way, both of you then make that very important decision -- to give yourselves totally to each other in marriage for the rest of your lives. Therefore, two important foundations of a marriage relationship are friendship and commitment.