We covered three important questions that I believe kids are asking about marriage: What is God's purpose for marriage? Why is it unwise to marry someone who doesn't believe in Jesus? What happens when people get divorced?
First: What is God's purpose for marriage? Genesis 2:24 gives us a very important recap of marriage - "Therefore a man shall leave his father and mother and hold fast to his wife, and they shall become one flesh." The "one flesh" idea will come back later on. But we see from the creation of the world that God created marriage to be a blessing to humanity, to glorify himself, and to be the best means by which to raise children. Marriage is a great blessing! It is hard work, to be sure, but to enjoy your marriage is one of the greatest blessings God has bestowed upon mankind. Having a strong, healthy marriage is the key to getting through the worst of times (speaking from a marries perspective, that is). And having a bad marriage makes any of the best of times difficult. God has also made marriage to glorify himself. When two people come together who love him and love each other, it's hard to find a better testimony of God's love, grace, patience, and forgiveness in action. Marriage sharpens two people together, it is the furnace through which God burns off sinful attitudes, selfish tendencies, and wrong belief. God also intends marriage to be the most beneficial way to raise children - two people lovingly bringing God's creation into the world to love the child, nurture him/her, and help them know Jesus.
Second: Why is it unwise to marry someone who doesn't love Jesus? Surprisingly enough, you will not find a verse that says "You can't marry a non-Christian!" This does not mean there aren't excellent reasons why you should avoid doing so, however - it's just important to be honest and know that there isn't a direct statement in the Bible like that. One of the best verses that helps us understand why we should avoid marrying a non-Christian is 2 Corinthians 6:14 - "Do not be unequally yoked with unbelievers." What does it mean to be "unequally yoked"? The farming imagery is used to describe something like an ox and a donkey being tied together (yoked) to plow a field. If two completely different animals are tied together, the work will be nearly impossible to do - they have different purposes, strengths, and are going to move in different directions. For a more extreme example, think horse and bunny... that one wouldn't go well for the bunny! The principle for marriage is that, if you marry a non-Christian, you are marrying someone with totally different values, beliefs, and expectations. You WILL move in different directions in life - and honestly, the most likely scenario is that the Christian will eventually give in and not lead a Christ-centered life. It is unwise because to join your life so closely with someone who doesn't share your love for God is to tie yourself up in immediate and long lasting conflict, and it is (mot likely) going to be very difficult to be a good witness together of the character of God.
Finally, what happens when people get divorced? We turned to Mark 10:1-12 for this one, where the pharisees test Jesus and ask him his thoughts on divorce. Moses had permitted men to give a certificate of divorce to their wives - a pretty easy process it seems! Jesus informs them that it was because of their hard hearts that this ended up being allowed, but from the beginning of creation (he quotes Gen. 2:24) God intended the two to become one, and says that what God joins together, no man should tear apart. And divorce is just that, a tearing apart of our lives because we have become one in life and purpose with the person we marry. Jesus equates divorce and remarriage (I know there is controversy over this, but sometimes that can't be entered into on nights like these) with adultery - there is still a life long commitment made before God to love this person until one of you dies. And that doesn't change in God's mind just because the state signs off on your divorce... harsh as that sounds. Divorce tears away at the fabric of our lives - like two pieces of paper glued together cannot be cleanly separated but will tear apart, so too with people's lives when there is divorce. Is there forgiveness available? YES! Is there healing that happens? YES! God is gracious, yet we need to understand that it is painful and not as God intended.
All in all, I hope it was a helpful night - it was helpful for me to (hopefully) put these big issues into fairly brief answers. Marriage is wonderful, fun, messy, hard, and beautiful at all times. Are you married? Bless your spouse today and thank God for him or her. Are you single? Ask God to make you into the kind of man or woman who will make an excellent and Godly spouse one day.