I've heard the verse on Romans 10 used a few times to explain that Protestant ministers are sent by God to preach the Gospel, verse 15 says: "How shall they preach unless they be sent?"
My question to those individuals is which Protestant ministers? Lutherans, Calvinist, Amish, Anglicans, Methodist, Church of God, Church of Christ, Quakers, Episcopalian, Salvation Army, Adventis, Presbytarian, Shakers, Wesleyan, Brethren, Church of Nazarene, or one of hundreds of splinter denominations from these?
The splintering of so many different denominations believing differently on key salvific issues is an important factor in showing the most obvious problems of finding the one who is truly speaking God's Word (Issues like "what kind of faith saves? Is baptism necessary? Needed? Is baptism for infants? Must baptism be by immersion only? Can one lose salvation? How? Can it be gotten back? How? Is the Real Presence true? Are spiritual gifts like tongues and healing for today? For everyone? What about predestination? What about free will?).
There seems to be two possible solutions to this dilemma, one is to be sent by extraordinary means and the other by ordinary means. Let's look at the extraordinary means. This method entails the individual to be sent by God personally. Seeing as there is a definite possibility that many will be deceived into believing they were sent by God there must be a way to verify their 'pedigree' as you can appreciate the difficulty in finding someone teaching God's Word amidst a sea of different ideologies and beliefs. Indeed, we find many instances in the Bible where these individuals sent directly by God performing supernatural signs to prove they were speaking God's Word (Exo 8:16-19; 13:7-16; 1 King 18:36-39; 2 Kings 4:15-17; Acts 13:6-11; Acts 3:5…). Most notably in John (3:2; 9:16; 11:47; 12:37), even Jesus admitted "Do not believe me, then, if I am not doing the things my Father wants me to do. But if I do them, even though you do not believe me, you should at least believe my deeds, in order that you may know once and for all that the Father is in me and that I am in the Father." (John 10:37-38).
But what about false teachers? They too will perform miracles. There's the problem, how can we discriminate between a true prophet and a false one? How are you to decide that question? The person who authenticates that prophet needs to be authenticated himself, and this authenticator needs to be authenticated as well all the way down the line. So who can decide whether a prophet is true or false? Well, the answer to that question is pretty straightforward: It's those who are placed in the ordinary capacity as God's teachers. To understand how this came to be, we need to look back at John 21:15-17
Three times Jesus asks Peter if he loves Him: "Simon son of John, do you love me?" And a third time Peter answers Him: "Lord, you know everything; you know that I love you!" And for the third time Jesus says to him, "Feed my sheep."
"Feed my sheep." These words are full of profound meaning. All through His Passion and up to His Ascension, Jesus seems to be acutely concerned of the future of His fragile little flock. On the night of His betrayal we find Jesus "deeply troubled", He lifted His eyes to heaven and called out a great high-priestly prayer for this ragged band of working men: "While I was with them, I kept them in thy name…But now I am coming to thee…Sanctify them in the truth." (John 17:13a, 17)
Sanctify them in the truth. Jesus has come to give humanity the words of truth given to Him by His Father. But now that the Son is going back to the Father, how will the world know that He was ever here? And that He really was sent by God? How will His work be preserved and continued? Would He commission His Apostles to write letters and collect them into a book, the Bible? No.
"I myself will be the shepherd of my sheep, and I will find them a place to rest. I, the Sovereign LORD, have spoken. "I will look for those that are lost, bring back those that wander off, bandage those that are hurt, and heal those that are sick … I will rescue my sheep and not let them be mistreated any more. I will judge each of my sheep and separate the good from the bad. I will give them a king like my servant David to be their one shepherd, and he will take care of them. I, the LORD, will be their God, and a king like my servant David will be their ruler. I have spoken." (Eze 34:15, 16, 22-24) It was in this context that we find Jesus, the humble carpenter, saying :
"I am the good shepherd, who is willing to die for the sheep. When the hired man, who is not a shepherd and does not own the sheep, sees a wolf coming, he leaves the sheep and runs away; so the wolf snatches the sheep and scatters them. … And I am willing to die for them. There are other sheep which belong to me that are not in this sheep pen. I must bring them, too; they will listen to my voice, and they will become one flock with one shepherd." (John 10:14-16)
But what happens to the flock once the shepherd returns to the Father? "I did come from the Father, and I came into the world; and now I am leaving the world and going to the Father" (John 16:28). As we wondered before, how will Christ's work be continued? If God's sheep starved for truth at the hands of false religious teachers under the Old Covenant, will not His New Testament flock again be defenseless after the Shepherd ascends back "to my Father and your Father, to my God and your God" (John 20:17)
The answer, according to the testimony of the early Church, lies in these words, spoken of the Good Shepherd to Simon Peter, representative of a simple band of Galilean fishermen: "Feed my sheep."
And what about a few years down the road, when there were wolves in sheeps clothing preaching in Jesus' name a different Gospel? In the years of Peter we find another shepherd tirelessly working among God's lost sheep. Like Peter, his given name is Simon, Simon Magus, he is the founder of the ancient heresy called Gnosticism, Christianity's oldest and most obstinate rival. Former disciple of Philip the evangelist, Simon apostatized to become the first person in recorded history to teach falsehood in the holy name of Jesus. He was in fact, the original fulfillment of one of Christ's darkest warnings: "Be on your guard against false prophets; they come to you looking like sheep on the outside, but on the inside they are really like wild wolves. You will know them by what they do." (Matt 7:15)
But what about the ordinary believers, how would they have reacted to a second set of "Christian" apostles preaching on their streets? Would it have been obvious that there was a wolf under the sheepskin? Yes. Jesus had said that we would know them by their fruits – but what if the fruits themselves can be counterfeited? Recall that Simon Magus had many "miracles" to his credit and a large number on converts as well. The Apostle Paul seems to be addressing this very dilemma when he wrote: "false apostles, deceitful workmen, disguising themselves as apostles of Christ. And no wonder, for even Satan disguises himself as an angel of light" (2 Cor 11:15)
The predicament was very real, if the prospective shepherds all look like angels how are they to choose between them? How on earth does a common Roman laymen in AD 50 – only just hearing of Jesus Himself for the first time – supposed to know which are the true disciples of Christ and which are the false? Do not underestimate this problem, we may casually imagine that these early believers had only to pull out their pocket New Testament to send these dangerous pretenders packing, tails between their legs. This was completely impossible; the Church had been preaching the gospel for at least 10 years before a single line of the New Testament was written. She had been doing these things for over fifty years before the final line was completed. And even then some may have been introduced to Matthew's Gospel and perhaps one or two letters from Paul – but even these would have been circulating as loose individual works; over 300 years would pass before they ever came to be bound together in one authoritative canon in a book we call our Holy Bible.
The solution is quite simple. When confronted with two conflicting stories, all one needed to do was find the "…man [that] was with Jesus of Nazareth" (Mat 26:71). He had simply to ask to traditional question: Which men had been with Jesus? That fact alone, once truly established, banished all doubt.
Jesus Christ appointed twelve apostles to teach His doctrines and exercise His authority once He ascended into heaven (Matt 28:16-20). He gave them specific authority to speak and teach what He taught (Eph 2:19-20, 1 Thess 4:2, 2 Pet 3:2), and He warned all of His followers of the consequences of private teaching outside of the Church (Matt 18:16-17, 1 Cor 5:5, 1 Tim 2:20, 2 Pet 1:20-21). Most importantly, however, Jesus promised the Holy Spirit to guide the Apostles in the truth (John 14:16-17), which would distinguish them from the false prophets who would later introduce false doctrines and heresies (2 Pet 2:1). This is the reason why St Paul described the Church as the 'pillar and foundation of truth' (1 Tim 3:15), and not the bible which can be twisted by the untaught and unstable (2 Pet 3:16). The only way that any group can claim to have the truth is if they teach what the Apostles taught, either written or oral (2 Thess 2:15).
But this begs the question: what happens after the original Apostles die? Is the Church not to continue the way Jesus established it in its hierarchical structure? If Jesus' words were not meant eternally and were to be understood simply in His time, then the authority of the Apostles which Christ instituted would have died with the last Apostle. This would leave the Church without leadership and in total confusion when serious doctrinal questions and problems occurred, which, inevitably, they did. (No point in relying on Scripture since many of the heretics used Scripture to defend their positions.) The other option, the much more likely and divinely consistent one, is that the Apostles would choose successors, passing on to them what they learned from the Lord, and in turn giving them not only the authority to teach but also the divine promise to correctly interpret God's written and inspired word. We know that this is the way it was done from the beginning by reading some of the Early Church Fathers.