A new visitor (hi!) to this blog recently asked the question of why Christians can’t marry outsiders. I think this is a good question worth addressing, and hope I can provide some useful insights. Comments from others are welcome, too, of course.
One thing to remember is that not all churches actually do prohibit mixed marriages. While some denominations do require a non-Christian spouse to convert, others are silent on the issue. It is really more of an issue of whether Christians should marry non-believers or not.
Concerns about marriages of mixed religions date back to the time of Moses. In Deuteronomy 7:3-4, the Israelites were prohibited from marrying outside of their religion because of the idolatrous practices of the pagans they lived among. A similar situation existed in New Testament times as well (2 Corinthians 6:14). The overwhelming concern was that marrying outsiders would ultimately lead to adopting their religious practices and falling away from God as a result.
I think the idea of whether marrying a non-Christian could lead to turning from God is an important one to consider. The choice of a spouse is one that needs to always be prayerfully considered, regardless of the circumstances. This is especially true if you expect to have children, since raising them in the Christian faith is important.