Read all of the Book of Galatians especially Galatians 3:10
We are not to tithe because this if from the Old Testament and only the Priests were tithing. If we tithe we would fall under the old law which no one is justified by the law.
For all who rely on the works of the law are under a curse, as it is written: “Cursed is everyone who does not continue to do everything written in the Book of the Law.”
Galatians 3:14 Christ has redeemed us from the curse of the law, having become a curse for us (for it is written, Cursed is everyone who hangs on a tree.”)