For a long time the question has been ask, "Which one of the churches is going to the kingdom of God, and which ones are not?" Because if you have to have be right about everything in religion to go to the kingdom, only one group can go. The group that was right.
The things that cause splits in churches are as numerous as verses in the bible. Why? Why does God have all of this divisiveness in his churches? Why do the churches keep arguing and splitting? Why wasn't God more clear on what he wanted from us like he did in the old testament? What is the purpose that God has in store for me? On and On and ON..... Isn't it great. Look at all of the debate that is had from the deliberate ambiguity. The puritans took themselves to a new continent because of their beliefs. Thus spreading the word of God. The dissension is not just a good thing, but a great thing.
After God divided the promised land among the eleven tribes of Israel. "Weren't there twelve?" Yes there were, please stop interrupting. The twelfth got no land. They got to be priests. Boy, I bet they were all thrilled with that decision about their future. Probably why they were so crappy at it. A portion of these priests were to go out unto the world and make converts of the other nations. Didn't happen. They sat around eating the food that was given in tithe and got fat. Only doing small portions of the job they were supposed to do, because they all stuck around instead of going out and spreading the word of God. Wow, what an effective use of manpower. (OK, you can't see it, but that statement is dripping in sarcasm.) So guess what, this system of choosing priests and giving exact direction got me what. A new false idol, every couple of years, a new god to be worshipped, and no one going out to be a missionary. Why not? Because they were told they had to.
The new way. Don't give direction, just give the prize at the end of the race. What does this do that the other way did not? Instead of it being demanded of you in the old way, in the new way it is freely given of the believer. Let me put it in the Blood Diamond way. "You, go dig for diamonds, but you can't have any." Not much fun, or very desired. But the new way is, "go out there and make me happy, and I will give you diamonds." What should I do to make you happy?", comes the reply. "You figure it out is the response." So what do we do to figure it out? We study the person the statement comes from to decide what will and what will not make them happy. Luckily there was a book written especially about them, telling their likes and dislikes. They discuss this with other people that want the diamonds. Some people argue about the best way to make their benefactor happy. They break into factions and separate themselves from others. They go out and ask advice of other people that they know and respect. They draw conclusions, and then go out and do what they think will get them the diamonds based on their interpretation of the book about the person giving the diamonds away.
Which way gets the commitment of the participant, being ordered about, or giving them something that they truly want as a result? Which gets more effort? Which gets more action? Which will accomplish the aim of God more readily?
The answer obviously is the new way. People are flat out inventing crap that makes God happy with us. They keep right on studying the word to find some new revelation that will give them the complete picture. But God didn't give it. So people argue over what it is, then split up. Spreading the word farther and farther and farther out across the world. Accomplishing exactly what God was trying to accomplish with the Levites. The people are committed on their own, not because they are forced to. Making the bonding even more permanent.
But down to the actual question. Who is right? The answer, most of them. "God protects his words". With this in mind, most churches have the big stuff right. How to allow God to save you? The five prerequisites, Repentance, Confession, Obedience, Belief in Jesus Sacrifice, and Faith in God, those are pretty much all taught in all churches. That is the important stuff, the rest of it is fluff. (In my opinion.) But those five prerequisites are more than enough to keep us occupied for a lifetime. So why does God make it so hard? To make it work the right way.