"Even so hath the Lord ordained that they which preach the gospel should live of the gospel" (I Corinthians 9:14).
This verse tells us that God has actually enacted an "ordinance" to the effect that Christian believers should provide financial support for those pastors and others who have been truly called by God to devote full time to the gospel ministry. Similarly, note I Timothy 5:18. "For the scripture saith [quoting Deuteronomy 25:4], Thou shalt not muzzle the ox that treadeth out the corn. And [quoting Luke 10:7], The laborer is worthy of his reward."
The latter clause also tells us incidentally that Paul regarded the Gospel of Luke as inspired Scripture with the same authority as the writings of Moses. In this verse, Luke was quoting the Lord Jesus as He was sending out His disciples on a missionary assignment.
The context in each of these passages indicates that it is not the responsibility of the Christian worker to plead with people to support him and his ministry, but rather the responsibility of those to whom or for whom he is serving. This principle that those whose income is from secular sources should support truly God-called, full-time Christian workers and ministries is thus really a divine ordinance.
But there is also another responsibility implied in doing this. Are the workers and ministries really true to the Word of God? Believers have been commanded to "try the spirits whether they are of God: because many false prophets are gone out into the world" (I John 4:1). Peter also warned that "there shall be false teachers among you" (II Peter 2:1), and Paul warned of those who would "by good words and fair speeches deceive the hearts of the simple" (Romans 16:18). God thus commands us to support those -- and only those -- who are truly God-called servants faithfully believing and teaching His Word. HMM