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1 Corinthians 16:1,2 -- On the first day of the week, each one should give as prospered. Some people are comparatively prosperous and should give more; others are comparatively poor and should give less.
Acts 11:29 -- Every man determined to give according to his ability. (See also 2 Cor. 8:12; Mark 12:41-44; Matt. 25:14-30.)
2 Corinthians 9:6,7 -- We should give generously as we purposed in our hearts, not grudgingly or of necessity, but cheerfully.
Just as the New Testament no longer requires animal sacrifices, the Levitical priesthood, the seventh-day Sabbath, the Old Testament holy days, and laws of clean and unclean meats, so it does not require the Old Testament practice of tithing. Rather Christians should support the work of the church by giving on the first day of the week according to their prosperity.
This does not mean we are free to give less than 10%. It might mean we should give more than that. We should give as prospered and purposed in heart.