This raises important issues for all Christians, yet only recently have I felt the need to re-check what I was brought up to believe, then to look again at what I saw in mainstream Protestantism when I became a Christian, then matters that have only very recently come to my attention - all to do with who have the responsibility for what has come to be called "the Great Commission", especially sharing the gospel and baptising.
My religious upbringing instilled into me that even children in the group were taking part in 'the Great Commission' by going round peoples' homes (with adults) trying to get people to learn the group's 'take' on the gospel. We all believed we were ministers of the gospel getting people to go through a set course of study, leading to baptism. This was without anyone going through theological seminary to obtain qualifications there. We disdained the 'clergy' class of Christendom; we were all unpaid volunteers. A few doing far more work than the others would get a tiny allowance for accommodation and to buy a few clothes. Teaching was open to all students in what was called "the Ministry School", with women teaching women and children, men taking the lead. Baptising was only done by a few men in good standing in the congregation. When I left that group after becoming a Christian, I then experienced the system used in Protestant denominations.
Then I saw a clearer distinction, with every Christian being encouraged to witness about their faith in Christ, to give an answer to all who asked them about their faith (as the Bible requires in 1 Peter 3:15). Correctly, that was no way the same as being an ordained preacher, or minister of the gospel. Those men (and they only ever have been men where I've been) were said to have "a calling to the ministry", and to be trained for it, before having hands laid on them in an official ordination ceremony. Only then could they stand up in front of a congregation and preach the gospel, and administer sacraments, including that of baptism. But there were 'lay preachers' and sometimes, if no qualified preacher was present, another man would fill the gap temporarily.
Yet this seems to have similarities with how a person could feel "a calling" to train as a nurse, or a doctor, or an engineer, or a politician etc. It seems enough for a Christian adult (or youth) to express a desire to become a minister, and after being checked out by the elders, enlist as a student in a theological college. After four years or so, and passing exams, they could be "called" by an interested congregation with a vacancy, and so begin as either an assistant pastor (usual for young men) or "the main man", receiving a wage to be "in charge" of the congregation. I never really thought about this (except for concern that only elders should teach - not youths.) Then this question arose.
Almost immediately I learned of an American group, N.A R. where one of its pastors preached to his entire congregation in front of him (and on the Internet) that Jesus said in Matthew 28:18, "All authority has been given TO YOU on earth..." I was shocked at what simply is the final outworking of misconstruing Jesus' meaning: blatant distortion of Jesus' own words, that would elevate people en masse to the level of the risen Christ, putting them on an authoritative par with him. This group trains men and women to become strident teachers, going out into the world to convert people to their religious system, and equating that with being converted to Christianity. Because they have been indoctrinated on the basis of unbiblical teaching, that THEY have all authority on earth given to them, the arrogance of some of them is breath-taking. Mainstream Christianity would not consider those ones to be ordained to teach or qualified to baptize.
Answer re. teaching and baptising: Jesus’ commission was to the 11 apostles he had initially chosen, and although Paul was later converted directly by Christ yet only baptised very few people, teaching and baptising required the authority of Christ. Those 12 had that. Other men were later identified and trained by them to continue that work, and so it ought to have gone on down through the centuries, to our day. But has it? How can it be that anyone who thinks they have “a calling” to the ministry, or fancies a salaried position over a congregation, can get trained, qualified in the eyes of their teachers, then have hands laid on them in an ordination ceremony, plus be the only ones supposed to baptise? At the time Jesus commissioned the apostles, there were thousands of Christians. Three thousand had been added to the Church on the one day of Pentecost alone! The book of Acts shows some mature Christians being drafted in to teach new converts. We are not told if mature Christians other than the apostles baptised converts. When persecution forced Christians to flee into other countries, they took the gospel with them, but was it only the apostles who spoke it into the world?
Answer re. spreading the gospel – the good news of Christ: This is not the same as teaching in the sense Jesus said in Matthew 28:19-20 because all Christians are charged with giving an answer to those who ask of them the reason for their hope in a risen Christ (1 Peter 3:15). All Christians are to be good witnesses for Christ, pointing others to the risen Christ and his return. When they publicly partake of the Lord’s supper, they make this declaration. Deeds are seen. Words that conform to such deeds are noticed. Hypocrites are rightly scorned by other people. All Christians must be exemplary in conduct and speaking, which is part of living for Christ as opposed to just supporting a religious system. When individuals who truly have the authority of Christ manifested in their Christianity speak and act, others notice a huge difference between them and those who only do so because that’s what they like to do, or think they ought to be doing.
Answers, but not a Conclusion: This whole matter needs to be re-examined by me before I can come to any conclusion. I have seen unchristian error with some groups misunderstanding, misapplying or downright distorting Jesus’ words in Matthew 28:16-20. Error seems to arise when Christians start thinking in terms of denominations, or religious systems. The ‘clergy/laity’ approach has led to huge swathes of people attending services of worship in buildings (wrongly called ‘churches’), sitting back to take in whatever spiritual food (or crumbs) individuals hand out from the pulpit, thinking it’s their job to teach and baptise; they only have to ‘support’ that kind of ministry. A sort of spiritual ‘back-up’ perhaps? Yet all Christians must actively spread the good news of the gospel of Christ. Of course, if they have not been taught the truth of that gospel, how can they do that? This is where teachers with the authority of Christ are needed. I’ve seen some such teachers in a wide range of denominations; some qualified according to Protestant ideas of proper ordination, others not.