“And by This Law Sanctify the Land of Zion unto Me”
Doctrine and Covenants 119:5–6
5 Verily I say unto you, it shall come to pass that all those who gather unto the land of Zion shall be tithed of their surplus properties, and shall observe this law, or they shall not be found worthy to abide among you.
6 And I say unto you, if my people observe not this law, to keep it holy, and by this law sanctify the land of Zion unto me, that my statutes and my judgments may be kept thereon, that it may be most holy, behold, verily I say unto you, it shall not be a land of Zion unto you.
President Joseph F. Smith said:
“By this principle (tithing) the loyalty of the people of this Church shall be put to the test. By this principle it shall be known who is for the kingdom of God and who is against it. By this principle it shall be seen whose hearts are set on doing the will of God and keeping His commandments, thereby sanctifying the land of Zion unto God, and who are opposed to this principle and have cut themselves off from the blessings of Zion. There is a great deal of importance connected with this principle, for by it it shall be known whether we are faithful or unfaithful. In this respect it is as essential as faith in God, as repentance of sin, as baptism for the remission of sin, or as the laying on of hands for the gift of the Holy Ghost.”
(Teachings of Presidents of the Church: Joseph F. Smith , 276.)