Let us look at what the Law concerning tithing says. De. 14:22-29 says "You shall surely tithe all the produce from what you sow, which comes out of the field every year. You shall eat in the presence of the LORD your God, at the place where He chooses to establish His name, the tithe of your grain, your new wine, your oil, and the firstborn of your herd and your flock, in order that you may learn to fear the LORD your God always. If the distance is so great for you that you are not able to bring the tithe, since the place where the LORD your God chooses to set His name is too far away from you when the LORD your God blesses you, then you shall exchange it for money, and bind the money in your hand and go to the place which the LORD your God chooses. You may spend the money for whatever your heart desires: for oxen, or sheep, or wine, or strong drink, or whatever your heart desires; and there you shall eat in the presence of the LORD your God and rejoice, you and your household. Also you shall not neglect the Levite who is in your town, for he has no portion or inheritance among you. At the end of every third year you shall bring out all the tithe of your produce in that year, and shall deposit it in your town. The Levite, because he has no portion or inheritance among you, and the alien, the orphan and the widow who are in your town, shall come and eat and be satisfied, in order that the LORD your God may bless you in all the work of your hand which you do."
If anyone truely wishes to observe the law and commandments concerning tithing, then they need to be able to carry out all that was written in this passage. For one thing, you would have to bring your tithe to the temple in Jerusalem, an impossibility since there is no temple. Secondly, this law was given to the Israelites to help support the Levites. Nowhere in the New Testament are we commanded or instructed to tithe. We are to give cheerfully, not under compulsion.