God’s plan for the support of His work on this earth is through the tithe and freewill offerings of His people. The tithe is the main source of funding for the total proclamation of the gospel to all the world by the Seventh-day Adventist Church. This includes a balanced and comprehensive evangelistic outreach to the public and the spiritual nurturing of church members. Because the tithe is reserved for a special purpose, freewill offerings must provide the funding for many functions of the gospel work.

Tithe Is Holy—The Bible makes it unquestionably clear that tithe is holy. It belongs to the Lord (Lev 27:30). This biblical principle is the very foundation of tithing. Since it seems to be a result of our labor, the tenth of our income may appear to be ours. But the Lord has stated that this is not the case. The tithe belongs to Him. This brings with it several implications. First, since the tithe is not ours, we have to return it to Him. This is the way the holiness of tithe is preserved. Using it for other purposes makes it common and violates its sanctity. Second, returning tithe is not a payment to a pastor or to any other person for benefits received from him or her. We do not give the tithe to humans; we return it to the Lord and He decides who should get it and how it is going to be used (Num 18:21, 24). Third, since tithe is holy, and, therefore not ours, it should not be used to put pressure on others in order to produce any change that we would like to see taking place. Nor should tithe be withheld in order to achieve a personal objective. The only thing we can properly do with the tithe is return it to the Lord in a timely manner as a sublime expression of love and respect to our Savior.

Source Adventist.org