@steaver :
You asked,
"What really makes a denomination or organization truly Christian?"
That, my friend, has been the subject of much debate and discussion for longer than you and I, put together, have been alive... and multiplied many times over.
To me, the
real problem is not one of confusing doctrines, but one of
"Who really has the Holy Spirit?"
" But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his."(Romans 8:9).
The Scriptures have many things to say about how the Spirit of God manifests themselves to and through God's people,
and here are a few of those references:
Romans 8:1-26.
1 Corinthians 2:6-16.
1 John 2:20-27.
Sweeping all of the doctrines aside, one can either get confused trying to sort them out, or read the Bible for one's self and then review what the differing groups are all teaching, and decide whether or not they are of God.
I can tell you which one(s) are the closest, in my opinion, and I can even tell you what that one ideal group will teach and preach...
Again, in my opinion.
But one thing that I cannot do is to make that decision for you.
"Who decides who is the true church?"
In reality, the Lord does.
If that's not enough of an answer, then I can tell you this, for sure...
It's
not the group that is guilty of ( or who promotes or tolerates ) the most ungodly behavior ( like murder, adultery, fornication, speaking evil of men, covetousness, etc ), loves this world and its ways, or tries to get you to give them your money ( through covetousness make merchandise of you, 2 Peter 2:1-3 )...and it is not the group that preaches and teaches works ( Ephesians 2:9 ), of any kind, as the reason that God saves anyone.
" Wherefore by their fruits ye shall know them."
Look for the fruits of the Holy Spirit ( Galatians 5:22-23 ), my friend, rather than the works of the flesh ( Galatians 5:19-21 ) and you
will find the people who are truly His.