Genesis 14:18-20

I began tithing shortly after I was baptized in 1968. Praise God for a preacher that preached on money. I have not regretted tithing one time since I started tithing.
Tithing is not a scheme to raise funds. Tithing is God's plan of raising men!

I. IT IS SCRIPTURAL. Principle of tithing is seen in the garden of Eden.
A. Commenced with Abraham (Gen. 14:18-20). 
B. Continued with Jacob (Gen. 28:20-22).
C. Commanded by Moses (Lev. 27:30-32)
D. Committed by Nehemiah (Neh. 10:37-39; 13:10-12). 
E. Charged by Malachi (Mal. 3:8-10)
F. Commended by Jesus (Matt. 23:23). 
  1. Tithing is not a substitute for personal service.
  2. Jesus practiced tithing (Mt. 5:17).
 
II. IT IS SENSIBLE.
A. Why would I do less under grace than an orthodox Jew was required under the law? Jesus never lowered the standards of the Law. He raised them to a higher level. (cf. Rom. 6:15)
B. Good investment (Mt. 6:19-20). A good investment is an investment in something long lasting (2 Cor. 4:18).
  1. Investment in souls.
  2. Investment in eternity.
C. A sign of allegiance (Mt. 6:24)

III. IT IS SPIRITUAL (2 Cor. 4:18)
A. A spiritual plan-- God's work (You are not spiritual when you withhold the Gospel from a world that needs it.)
B. A spiritual purpose-- To please God. (You are not spiritual when you use your money in a way that displeases God.)
C. A spiritual practice-- Contrary to the flesh. (You are not spiritual when you live according to the flesh)