Jesus Set It Up
The book of Ephesians tells us Christ gave some to be Apostles, prophets, evangelists, pastors (or elders) and teachers. Paul tells us why some people are given such responsibilities, "to equip [Christ's] people for works of service". Then he tells us why this is necessary, "so that the body of Christ may be built up until we ALL reach unity in THE faith and in the knowledge of the Son of God and become mature, attaining to the whole measure of the fulness of Christ". (Vs 11-13, CH-4)
Jesus had a purpose when He placed structure in the church. He needs elders to be mature and firmly grounded so they can ensure His word is rightly divided or accurately handled so it can be taught truthfully and completely (2 Tim 2:15). Elders need to be teachers themselves, but also to shepherd the evangelists (preachers) and others in the church as they teach and proclaim His Word. Jesus makes sure these are in place so that His message can be properly taught in truth and love. In the absence of Jesus' structure, there would be chaos, and people chasing after every new idea, strange thought and even evil intent that is out there. That's one reason it's so important as Christians, that when we want to read and study, we pursue what people in His church teach, and not just anybody with a good book to sell or a TV show.
In the follow-up verses in Ephesians, we see more reasons why Jesus set it up this way. vs-14, "Then we will no longer be infants, tossed back and forth by the waves, and blown here and there by every wind of teaching and by the cunning and craftiness of people in their deceitful scheming." False teachers will try and draw people after themselves for various dishonest reasons, (Acts 20:30) sometimes greedy financial ones. Some teach out of ignorance with no evil intent, but no factual scriptural foundation either.
Paul ends this thought by saying that instead of letting cunning and crafty people throw every new idea at us, which may cause us to be like a child looking at a shiny new toy, that amongst brothers and sisters in the church we should "speak[ing] the truth in love, [so that] we will grow to become in every respect the mature body of Him who is the head, that is, Christ." (vs 15)
There is a reason Jesus doesn't want us to listen to every good sounding preacher or read every so called best seller religious book that comes along, because Satan uses these like the wind blows the waves, and can toss us around (keep us confused as to THE truth), especially when we are not yet mature in the Word. He wants us, His body - the church, to be constantly growing toward maturity. That's our best weapon against Satan, who is behind all that cunning and craftiness that Paul warns about. The devil can even lead the most mature down the wrong road if we let our guard down.