Marriage in Heaven

I often hear this question from unmarried people, and occasionally from a spouse. The unmarried want to know because if there’s no marriage in heaven, they want to get married and have children now. I’m not sure why those who are married ask the question, but in most cases it appears they would like to continue the relationship in heaven. (In some cases they may be looking forward to being free from the relationship!) The Bible provides a clear answer that seems to create a theological problem.