These come from Francis Chan’s book Crazy Love (excerpts taken from pp. 68-71):
Lukewarm People attend church fairly regularly. It is what is expected of them, what they believe “good Christians” do, so they go. (ref. Isa. 29:13).
Lukewarm People give money to charity and to the church . . . as long as it doesn’t impinge on their standard of living. If they have a little extra and it is easy and safe to give, they do so. After all, God loves a cheerful giver, right? (I Chron. 21:24).
Lukewarm People tend to choose what is popular over what is right when they are in conflict. They desire to fit in both at church and outside of church; they care more about what people think of their actions (like church attendance and giving) than what God thinks of their hearts and lives (Rev. 3:1).
Lukewarm People are moved by stories about people who do radical things for Christ, yet they do not act. They assume such action is for “extreme” Christians, not average ones. Lukewarm people call “radical” what Jesus expected of all his followers (Jas. 1:22, 4:17, Matt. 21:28-31).