frustration

Yesterday we were studying 1 Corinthians 12:12 - 31 on body life.  I had three main points about body life.
1. It is based upon a confession. 
2. It involves diversity of people, gifts, etc.
3. It involves unity in Jesus Christ.
So why was I frustrated?
I was frustrated because we want diversity where God wants unity and we want unity where God wants diversity.  The first part was not a big problem in my class but the unity in confession became a much larger problem.  I suggested that we begin with the Apostles' creed but not everyone would agree there.  However, those that did agree wanted to add more.  Where we have unity is the fundamentals of the faith.  We need to agree on the God head and the Gospel.  So then what about creation, inspiration of Scripture, end times, women in ministry, baptism, etc.?  I am not saying and I wasn't saying that our stand and understanding of these things is not important but should they divide us so that we cannot have fellowship?
Just an observation on the area of unity where God says we should have diversity.  Some want us to believe that the reformation is over but the issues that led to the reformation are still there today.  We cannot ignore them, they are foundational to the Gospel.  Salvation is by grace through faith and we cannot add anything to it.  Most Catholics and many Protestants, even evangelicals want to add something but then we are not adding but subtracting. 
Someone said that I should not be surprised that we had disagreements.  After all I should not expect that everyone be like me.  Where then is the diversity?