Tithing is the practice of regular donation from personal income. It is practiced by various religions.
- 10% of income is often quoted as the proportion to give by some Christian denominations,  although it is unclear if it should be applied to net or gross income. It is also sometimes considered as a recommended minimum.
- about 23% as a minimum is the rate of various tithes in the Old Testament. 
While some Christian denominations practice tithing, many Christians disagree that tithing is necessary. Some Christian churches consider tithing to be replaced by "whatever you can afford" from 2 Corinthians 9:5-8 . This might be a case of selective use of Old Testament law.
Arguments for tithing
- an act of worship 
- reminder of dependence on God 
- maintain church buildings
- its God's money anyway, keeping it is stealing 
- investment for the future i.e. to "store up treasures in heaven"
- "[...] any church or ministry who does not teach God's Plan of Bible tithing is not of God and is not a legitimate church or ministry[...]"