You ask a very important question for there is so much confusion on this topic. You are right in pointing to the change in priesthood, for under the Law of Moses it was the “Levitical priesthood” (see Hebrews 7:11) with Aaron being the first “high priest” (Hebrews 5:4). Under that priesthood men were required to “bring tithes and offerings” to the Levitical priests in order to support them (see Numbers 18:21, 26; Deuteronomy 12:5-6). Today we are living in the “Dispensation of Grace” with Christ as our Great High Priest (see Hebrews 4:17). His Priesthood is after “the order of Melchizedek” (Hebrews 5:5-10) which is altogether different than the Levitical priesthood. To see the great change in priesthood and the differences between them I would encourage you to read Hebrews chapter 7.

It is sad that there are pastors and bishops who command people to bring tithes and offerings to the altar for them to announce blessings to the giver, for there is no such instruction in any of the New Testament epistles. Again, “under the LAW” men were required to do so in order to support the priests ministering to the people, but “under GRACE” God blesses believers freely through His beloved Son. In Romans 8:31-32 we read, “What then shall we say to these things? If God is for us, who can be against us? He who did not spare His own Son, but delivered Him up for us all, how shall He not WITH HIM ALSO FREELY GIVE US ALL THINGS.” God has, first and foremost, blessed us with “SALVATION through His Son’s death on the cross,” and after one is saved, he/she continues to be blessed by pure GRACE through His Son. We see this precious truth in Ephesians 1:3, “Blessed be the God and Father or our Lord Jesus Christ, WHO HAS BLESSED US WITH EVERY SPIRITUAL BLESSING IN THE HEAVENLY PLACES IN CHRIST.” We don’t have to “work or pay for those blessings”; they are ours based on our eternal standing “in Christ.” Our “spiritual leaders” have no right to “announce blessings to the giver,” for we just saw that “God has announced the blessings He has given us in Christ.” He is the GIVER and the ANNOUNCER of the blessings!

So, this begs the question, “Why do ‘spiritual leaders’ today teach these things?” They teach this because they still think we are “under Law” and that we must “earn God’s blessings through works (including the giving of tithes).” God wants us to be “giving” to meet the needs of others, but we are NOT COMMANDED TO DO SO. Here are some verses with some of the PRINCIPLES OF GIVING for those who are living UNDER GRACE: “Now concerning the collection for the saints…let each one of you lay something aside, storing up AS HE MAY PROSPER…For if there is first a WILLING MIND, it accepted ACCORDING TO WHAT ONE HAS, and not according to what he does not have. For I do not mean that others should be eased and you burdened; but by AN EQUALITY, that now at this time your abundance may supply their lack, that their abundance also may supply your lack—that there may be EQUALITY…So let each one GIVE AS HE PURPOSES IN HIS HEART, not grudgingly or of necessity; for God LOVES A CHEERFUL GIVER” (1st Corinthians 16;1-2; 2nd Corinthians 8:12-14; 9:7). We learn here that we should be giving 1) As the Lord has prospered us; 2) Willingly and cheerfully, and 3) To meet the needs of others. Under the law men were required to TITHE, which means they had to give 10% of what they had, but under grace men should give according to their ability. It may be 10%; it may be over 10%; it may be less than 10%. We give because we WANT TO, not because we HAVE TO. And we give to meet the real need of someone and it may be that we ourselves will be in need someday and receive the gifts of other believers. Again, under the law tithes were given to support the Levitical priests; today ALL BELIEVERS ARE PRIESTS (see 1st Peter 2:4-5 with Hebrews 13:15-16) and thus we “minister to one another.”  (DO)  (496.3)