Even when God DID use an organization (the Israellites), it was not wrong to disagree and teach truth. Jeremiah spoke against the organization of his day and was effectively df'd for it.
What organization did Noah belong to? It was just a family arrangement. What about Abraham? Joseph? Jacob?
God dealt the families and individuals except with the nation of Israel. When Jesus included the gentiles in that "group", there was no NEW organization established. See how God established Israel? Didn't happen again in the early church. There were people that continually questioned what was being taught. The Boreans are a great example. They wouldn't even accept the apostles teaching unless they were convinced from scripture.
Then the brethren immediately sent Paul and Silas away by night to Berea. When they arrived, they went into the synagogue of the Jews. These were more fair-minded than those in Thessalonica, in that they received the word with all readiness, and searched the Scriptures daily to find out whether these things were so. (Act 17:10-11 NKJV)