If you love someone do you think you always will?

no, especially if you marry someone else. Love is fleeting, unless it's the love of a mother and child.

Perhaps when you are first married you may feel this way and am sure some people do stay in love forever. Waiting until you are older may help, as you are more mature and may be able to rationalize a bit better about how you feel. If you look at the divorce rate, I think that it may be safe to say, no, it is not reasonable to think that you will always be in love with the same person. People and circumstances change, that is not to say you will fall out of love, but it is a very real possibility.