One of the things Jesus never actually said was, "By the way, now that I've introduced grace into the equation, no one needs to worry about tithing anymore."
Tithing is considerably less popular than words like generosity or sharing. Among lay people the most common question associated with tithing is: "Am I supposed to base it on net income or gross?" Among pastors the question is: "Isn't tithing an Old Testament concept? Aren't we under grace now?"
This question more or less assumes that it was only post-Pentecost that the church discovered that God is the owner and that people are stewards. It implies that legalistic old Israel thought all they had to do was check the "I tithed" box and then got to spend the rest however they wanted (ignoring biblical statements like "The earth is the Lord's and the fullness thereof").
Worse—a certain looseness of thought about grace sometimes becomes a rationale for not giving at all. A friend of mine made the case: "If my kids are really the Lord's, then I can count the money I spend on their food and clothing and college tuition as falling into the 'good steward' category. If I use my home for hospitality and hosting small group, then the same goes for furniture acquisition and home makeovers. I use my computer for Bible study and my phone to store worship songs, so those items are stewardologically deductible." This type of "all-grace giving" where we give "everything" to God looks suspiciously similar to giving nothing to God.
What if tithing is actually one of God's great gifts to us? What if tithing isn't opposed to grace, but is actually a vehicle of it? I'd like to go back to one of the classic statements about the tithe in Scripture, and look at why tithing is in fact God's great tool to create generous people.
Spiritual training wheels
Tithing is like training wheels when it comes to giving. It's intended to help you get started, but not recommended for the Tour de France.
How do you know when to take training wheels off? The quick answer is: when they're slowing you down. How do you know when its time to stop tithing? For all of us not living in dire poverty, the answer is when you're giving way more than 10 percent. Tithing is a bad ceiling but an excellent floor.
The prophet Malachi famously spoke of failure to tithe as a kind of robbery of the divine. "'You are robbing me. Bring the whole tithe into the storehouse, that there may be food in my house. Test Me in this,' says the Lord Almighty, 'and see if I will not throw open the flood gates of heaven and pour out so much blessing there will not be room enough to store it.'"
God invites human beings into an experiment. He challenges people to test it. At the same time, failure to tithe is called robbery. Tithing is not the last word in generosity; it's the first word. But it's a word that God takes with deep seriousness; perhaps because when human beings get vague around finances, they grow deeply evasive.
Tithe was never to be legalistic
Tithing was built into the foundation of Israel's way of life. "A tithe of everything from the land, whether grain from the soil or fruit from the trees, belongs to the Lord; it is holy to the Lord" (Lev. 27:30).
The word tithe means "a tenth part." Tithing means 10 percent. For Israel, however, tithing was really only a start.