Is it proper to refer to a church building as "the house of God"? I've often wondered about this because God doesn't live in a building, does He? — D.McC.
No, God doesn't live in a building, no matter how beautiful or how simple it may be. As Paul told the people in Athens, "The God who made the world and everything in it is the Lord of heaven and earth and does not live in temples built by hands" (Acts 17:24).
That doesn't mean a church or other building isn't part of God's plan -- because it may be. As God's Word is preached there... as people pray and worship God there... as they celebrate the sacraments and other sacred events there... God will use it as a tool in His hands. It's only a tool -- but it's still one God can use for His glory.
This doesn't mean, however, that it's necessarily wrong to refer to a church as a "house of God," or to speak of a camp or conference center (for example) as a place that God uses. Every church building should remind us of God; every place that's been set aside for His service should remind us of the life-changing power of the Gospel. God may have spoken to us in a particular place, and years later He may use that memory to lead us to renew our commitment to Christ.
The most important thing, however, isn't the building where we worship, but the sincerity and openness of our hearts when we go there. Are we seeking God's will, and are we listening for His Word? Jesus said, "For where two or three come together in my name, there am I with them" (Matthew 18:20).