Depends on what you call “unity.” There’s a difference between “unity” and “conformity.” The former can be achieved spiritually without total outward conformity. However, the latter can be totally achieved without true spirituality. For instance, Jesus said to the church at Sardis, “I know your deeds, that you have a name (outward appearance) that you are alive, but you are dead.” When Jesus prayed that we be “one” in Him, He was not praying for outward, religious conformity.Well, if one read the Bible he would soon see that it is not men who are building the Church, but Christ Himself. So I agree, the Bible is not a blueprint on how to build a church, but it tells us who and what it is and on what foundation Christ Himself is building it.
I disagree, however, that one cannot know 100 percent of the faith through the 66 Books of the Scriptures. What do we know about Christ and salvation that is not revealed in the Bible?