Jesus said, “All authority hath been given unto me in heaven and on earth” (Matt. 28:18). Christ is the head of the Church and he proclaimed the Church his, "...and upon this rock I will build my church; and the gates of Hades shall not prevail against it. I will give unto thee the keys of the kingdom of heaven” (Matt. 16:18, 19). The Lord gave the great responsibility of Church leadership to spiritually mature men (I Timothy 3.1-7 and Titus 1).
Elders are qualified men whom God gave the authority of oversight (Acts 20:28) to the local flock in which they belong (1 Peter 5:2). These are men of character, principal, and discipline to God's Word. They shepherd the flock tending to spiritual matters and guarding against false doctrine.
Deacons are qualified men God authorized to serve his Church (Acts 6 1-4). They take care of physical responsibilities while the elder take care of spiritual responsibilities. Deacons, under the elders, maintain the building, the grounds, needy saints, equipment, and other such matters.
Evangelist are knowledgeable men who teach God's Word in love and truth. They preach that Jesus is our hope (1 Corinthians 15 19-22), our example, and his Word is our one and only guide (2 Timothy 3:16-17).