The publisher of Forbes, Rich Karlgaard, has an interesting article on tithing . There are arguments pro and con on whether this Old Testament practice is required of Christians today (I vote yes), but perhaps a unifying point is that we should put our money where our mouth is. By tithing, we put our money in a heavenly vault that will never be broken into by thieves, and we invest in a currency that will never be eaten by inflation. We express faith that God offers riches now and forevermore that are far superior to anything offered by the world.
Tithing creates a sense of peace, because our wallet is in alignment with what we believe. If you asked longtime tithers, the guess is that they would rather be beaten with a truncheon than quit tithing.