S: 2 Kings 8:16-17 Jehoram son of King Jehoshaphat of Judah began to rule over Judah in the fifth year of the reign of Joram son of Ahab, king of Israel. Jehoram was thirty-two years old when he became king, and he reigned in Jerusalem eight years. But Jehoram followed the example of the kings of Israel and was as wicked as King Ahab, for he had married one of Ahab’s daughters. So Jehoram did what was evil in the Lord’s sight.
O: Jehoshaphat was a king who was serious about following God, and God had given him a great victory over an invading army, as dramatized in this cool song by Don Francisco and told in 2 Chronicles 20.
However, he was friends with Ahab and allowed his son to marry one of Ahab's daughters. She in turn influenced Jehoshaphat's son Jehoram to stop following the Lord and become evil.
A: There are many other passages in scripture showing examples of people who married people who did not follow God and hence were led astray. Another famous example was Solomon, whose marriage to a princess of Egypt and other women who did not follow God led him astray as well. That's why it is a principle in scripture that you should only marry those who share your faith.
And it's not just men: 1 Corinthians 7:39 mentions that "the woman is free to marry any man she wants, but he should belong to the Lord." (The context is a widow whose husband has died, but I don't see any reason this shouldn't apply to a woman who has never been married before, either.)
Yes, there are some cases where someone did marry a nonbeliever who later became a believer (I personally know two) but the vast majority it is the other way around that happens -- the believer's faith cools and the family makes most of their decisions without reference to God's principles.
P: Father, I thank You for the wonderful wife you have given me. I thank You that she follows You and encourages me to follow You. In Jesus' name, amen.
Note: this is using the SOAP method. For more information, see this page (not written by me.)