Answers
Believers differ here honestly. Some hold that the tenth is a standing creation-order principle that predates the law and still stands; others hold that the New Testament replaces a fixed percentage with proportionate, planned, cheerful giving that for many should exceed a tenth. Both sides agree on this: give deliberately, give regularly, give with joy rather than under pressure, and treat any teacher who makes a blessing conditional on a payment as the Bible treats him.
Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver.
2 Corinthians 9:7
Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.
1 Corinthians 16:2
Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the LORD of hosts, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it.
Malachi 3:10