Let me start by saying that there are reasonable, biblical grounds for divorce--but God hates it anyway (Malachi 2:15-16)
Sin is the only reason for divorce. Someone or some people sin against each other and against God, and the marriage falls apart. Well, truthfully, nothing is sound for those who forsake God's commandments. There are two things which God commands us to do, basically:
Love the Lord your God with all your heart, soul, mind, and strength.
Love your neighbor in the way that you love yourself.
There is no love of God in the heart of a man or woman who commits adultery. There is no love of God in the heart of a man who abuses his wife. There is no love of God in the heart of a man or woman who does wickedly and denies it (1 John 1:8-10).
It is infuriating and saddening to watch "break-up" after "break-up" of family after family around this country. It doesn't matter who the couple is, it doesn't matter how old they are, or how many children they have (if any). It's still sad, still infuriating. It seems that loving one's neighbor, is more important than loving one's wife. And that loving oneself is supreme above all.
Fact: you will never stop loving yourself, so quit worrying about it. Self-love is never taught in the Bible because it is assumed (Proverbs 16:26; Ephesians 5:25-33).
Fact: the more you focus on loving yourself, the less you will focus on loving God, and in turn loving your neighbor: thus, a focus on self-love becomes a dangerous sin-trap for those who follow it.
Fact: divorce hurts more than just your spouse and you. I don't have to quote the stats for how the children turn out. I don't have to do extensive interviews for the number of people that are discouraged, "Well, if they can't make it, how can we?" And I shouldn't have to quote the numerous Bible passages that warn against adultery, but I will reference a few: Matthew 19:4-9, Mark 10:1-12, Hebrews 13:4, 1 Corinthians 7, and, of course, Exodus 20:14.
So how do we avoid the issues that break so many couples apart?
1) Avoid fornication. Previous fornication is the most prevelant cause of adultery. If you don't hold out for "the one," it will be infinitely harder for you to hold in for "the one."
2) Be patient. Be patient selecting a spouse if you are not yet married, be patient with your spouse if you are married. It is not easy deducing the faults of a person who charms you, but time is the truest test. It is also not easy dwelling with another sinner, but you have no alternative: "For all have sinned..." Let love cover a multitude of sins--and don't abuse your spouse's love when you are tempted to sin.
Where does this unmarried 24-year-old who has never had a girlfriend get off telling you how to stay married? From watching people who don't obey God ruin their own lives and the lives of those they love. It is heart-breaking. Don't follow them.