Self defined

I wonder, why is it that so many people think that they can define for themselves, the character of God, the picture of heaven, the form of worship and the structure/laws of faith?  As Dr. Bahnsen (one of my religious mentors) used to say, "The Christian faith is not a wax nose.  We cannot form it however we please."  The historic Christian faith has been defined and articulated by the apostles, the seven ecumenical councils and the living Church.
As feeble, inarticulate and vascillating individuals, with an incredibly limited knowledge of history and even ourselves, we cannot, even must not, think that we can rightly articulate the Christian faith.  We must think of ourselves as one in the body of Christ, not individuals.