The word tithe comes from the Hebrew word for “tenth” and refers to the Old Testament requirement that Israelites give 10% of their goods (animals or produce) for various purposes and events. In fact, the Old Testament Law required multiple tithes—one for the Levites, one for the use of the temple and the feasts, and one for the poor of the land—which would have pushed the total to around 23.3 percent.4
Here are a few Old Testament examples:
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. -Leviticus 27:30
I give to the Levites all the tithes in Israel as their inheritance in return for the work they do while serving at the tent of meeting. -Numbers 18:21:
Honor the LORD with your wealth, with the firstfruits of all your crops. -Proverbs 3:9
While the New Testament doesn’t instruct every Christian to give 10% of their income to the church, it does encourage believes to give regularly (1 Corinthians 16:2), cheerfully (2 Corinthians 9:7), sacrificially (2 Corinthians 8:3-5), and proportionally ( 2 Corinthians 8:11-12).
When considering the Old Testament standard for Israelites to give 10-20% of their income away, why not aim for a similar percentage? As Randy Alcorn says,
There's a timeless truth behind the concept of giving God our firstfruits. Whether or not the tithe is still the minimal measure of those firstfruits, I ask myself, "Does God expect His New Covenant children to give less or more?" Jesus raised the spiritual bar; he never lowered it.
In principle, we would encourage every Christian to be working towards giving 10% or more of their income away each year to the local church and beyond. Start somewhere and take your next step in stewarding God’s resources. If you’re currently giving 2% of your income, what would it look like to give 3%? If you’re giving 7% of your income, what would it look like to give 8%? If you’re giving 15% of your income, what would giving 16% look like?
4 gotquestions.org/tithing-Christian.html