"Even from the days of your fathers ye are gone away from mine ordinances, and have not kept them. Return unto me, and I will return unto you, saith the LORD of hosts. But ye said, Wherein shall we return?
Will a man rob God? Yet ye have robbed me. But ye say, Wherein have we robbed thee? In tithes and offerings. Ye are cursed with a curse: for ye have robbed me, even this whole nation. 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. And I will rebuke the devourer for your sakes, and he shall not destroy the fruits of your ground; neither shall your vine cast her fruit before the time in the field, saith the LORD of hosts."
Now, let us consider the following four words: "nation", "tithe", "storehouse", "high priest".
1. The Nation
Malachi is one of the six undated prophets. This book was written during the years after the return of Israel from the Exile in Babylon. Malachi shows that the Temple worship, with its sacrifices, had been fully restored. However, Malachi also shows that the ceremonial formalism and hypocrisy which come to a peak in the days of our Lord’s earthly ministry, four hundred years after Malachi’s day, were even then actively at work. For example, consider Malachi 1:7-8 where we read how the people offered the poorest animals for sacrifices, those that were blind, lame, and sick, while they kept the best for themselves. Such practices were directly contrary to God’s command found in Leviticus 22:20-22.
2. Tithes
Furthermore, according to Numbers 18:21 and Deuteronomy 14:22-29 the tithes and offerings were a legal obligation on the part of the eleven tribes of Israel, and were to be brought to the storehouse adjoining the Temple, to be given in their entirety to the Levitical priesthood for two years. Then on the third year they were to be given, not just to the priesthood, but to all the destitute such as the fatherless, the strangers, and the widows. Therefore, to withhold the tithe was in a very real sense robbing God. Because of their disobedience, God pronounced a curse upon the nation. What was this curse? That God would close the windows of heaven and withhold the rain - drought and famine would follow. If Israel again became obedient in bringing the tithes and offerings, God would again open the windows of heaven and pour out abundance of rain - the crops would be plentiful harvests (See also 1 Kings 8:35, 36 and 2 Chronicles 7:13).
3. Storehouse
The storehouse of Malachi’s day - Old Testament times - was a large, three story building adjoining the rear and two sides of the temple. This storehouse was for the purpose of storing all the tithes and offerings which were brought to the Lord. No such Temple with its adjoining storehouse exists today.
4. High Priest
Tithing is no longer required for one last and most oblivious reason for those who have read and studied the word of God...We have a high priest that has no need for ten percent of your earnings or what you own.
"And being made perfect, he became the author of eternal salvation unto all them that obey him; Called of God an high priest after the order of Melchisedec. Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing. For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. For every one that useth milk is unskilful in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil."
(Hebrews 5:9-15)
And finally this, along with other Scriptures your pastor may not have adequately explained to you:
Brethren, be no more children tossed to and fro and carried about with every wind of doctrine by the slight of men and cunning craftiness whereby they lie in wait to deceive (Ephesians 4:14); but be rooted and built up in Christ and established in the faith (Colossians 2:7), standing fast therefore in the liberty wherewith Christ hath made us free and be not entangled again with the yoke of bondage. (Galatians 5:1)