Though we are not under Jew 'tithe" laws, the New Testament teaches that every Christian, as a good steward, is morally obligated to support their local church financially. Why the obligation? Because every Christian is an eternal beneficiary of the church's Word and doctrine preached within their local assembly (1 Tim 5:17-18). It is a Biblical fact that the Levite ministers of the Old Testament temple were fully supported by Jewish tithes (1 Cor 9:13).
Now, under the New Testament, cheerful and bountiful offerings supersede the parsimonious and grudging 10% tithes of the Old Testament. Therefore, under our present marvelous graceful dispensation, we should abound in giving proportional to our monetary bounty, and in view of the eternal benefit delivered unto us by our ministers (2 Cor 9:6-7).
Consequently, every pastor who preaches the gospel with good doctrine and sound speech, and every missionary who is worthily "approved by letters" should be able to live of the gospel (1 Cor 9:14, 1 Cor 16:1-3). There is a second sense of moral obligation not derived from any personal benefits, but in light of the giver's innermost god-like mercy toward others (Mat 5:7). Here, every Christian should give to those who have legitimate qualified needs, and to the poor (1 Tim 1:10, Gal 2:10, Eph 4:28).