Though seemingly not directly related to our study of the tithe, an additional question requires consideration...
Did Jesus say that all of the Law is still in effect during the church age (New Covenant)?
One church document used Jesus' statement in Matthew 5:17 to justify their belief that the tithe, as part of the Law, was continued into the New Testament church. Consider for a moment that verse and the one that follows it.
Jesus was teaching that He was not arbitrarily abolishing the law. Further He was clearly saying that it could never be abolished but required fulfillment. Once fulfilled it is done away with by completion! This Bible passage cannot be randomly used to justify carrying on any one practice, or aspect, of Mosaic Law. If this passage could be used to continue the tithe, why not continue sacrifices, or putting witches to death (Exodus 22:18), celebrating all the mandated feasts (Exodus 20:15-19), etc.? For those who try and narrow it down to only carrying forward passages which promise blessing, consider one more example:
Now assume that this still applies for the church, of course changing the word Israelite to mean any believer. How many believers are following through on not charging interest to other believers, or even think of this as an issue?
It is a blatant misuse of Scriptures to say that the Matthew 5:17-18 passage means all practices of the Law go on forever and even worse when it's used to justify only one pet practice. By Jesus' own words, if He fulfilled the Law (in any aspect) that part of the Law could be finished. It's on this basis that the New Testament church no longer carries on the sacrifices, ritual, festivals, and legal ordinances of the Mosaic Law (read Hebrews chapter 10).