When did church become about having authority over people?
Obey them that have the rule over you, and submit yourselves: for they watch for your souls, as they that must give account, that they may do it with joy, and not with grief: for that is unprofitable for you. (Heb 13:17)
Oh that's right, the Romans.
But Jesus called them to himself [and] said, “You know that the rulers of the Gentiles lord it over them, and those in high positions exercise authority over them. It will not be like this among you! But whoever wants to become great among you must be your servant, and whoever wants to be most prominent among you must be your slave— just as the Son of Man did not come to be served, but to serve, and to give his life [as] a ransom for many.” Matthew 20:25-28
The context here is that the apostles were operating in the flesh at this time, and competing for the highest position in Christ's literal Kingdom. Indeed the mother of James and John, the sons of Zebedee, was well-meaning but rather ambitious for her sons, and petitioned the Lord to make sure that they would sit beside Him in His coming kingdom (taking the highest positions). So this was all about ambition, even though these men loved God and Christ. Therefore we have this saying of Christ quoted above, which was teaching the lesson that the one who is the greatest in humble service is also the greatest in the Kingdom of Heaven. And among these Christ Himself was the greatest Servant, and He illustrated this by washing the feet of His disciples.
Does this saying mean that Christ was nullifying legitimate authority within the churches and within the Kingdom of God? Not in the least. It is God who raises up genuine elders within the churches and gives them oversight authority over the flocks. The meaning of episkopos (bishop) is "overseer" -- one who not only rules, but ensures the welfare of the flock through his diligent oversight. So elders were pastor/elder/bishops. Furthermore, Christ promised the apostles that in His Kingdom they would sit on twelve thrones RULING the twelve tribes of Israel. So legitimate authority is a necessity in the churches and in God's Kingdom. And that is why 24 elders are seen surrounding the throne of God in Heaven. The number 12 is the number of Divine government, so 12 x 2 means double the emphasis on government.