I believe Dr. Blackwood taught me that three forms of government were taught in the scriptures. Hierarchy, Presbyterianism, and Congregationalism. That is if I remember correctly.
He made a case from the scriptures for each one. He was convinced Presbyterianism was the order set from acts 15. I am not convinced that Acts 15 is the place to really plea for the cause though.
http://www.reformedbaptist.co.uk/Wha...0Jerusalem.htm
Here is an old thread where we discussed the differences a bit here and the article I linked to above.
Congregational vs. Presbyterian
I have grown more stronger in my convicition that Plural Elder rule Congregationalism is more biblical.