We modern evangelical and pentecostal pride ourselves for having no creed but the Bible. We pride ourselves as having no tradition and no religion. The interesting part is if this rallying cry of 'no religion' is still Christianity - it may be different.
Firstly the a-creedal (that means no creed) philosophy of evangelicals/ pentecostals makes the movement very vulnerable to erroneous teaching. They do have statements of faith but they are very brief indeed such that any preacher/ teacher who does not hit upon items in the statement of faith will be acceptable. Here is where erroneous teaching can creep in because any Tom/Dick and Harry will be ok too so long as he/she is not blatantly counter their statement of faith - the major items.
An example of this is the idea of having faith in one's faith. Sometimes there is a default mode present specially among young people that places faith in one's believing, that is - placing one's good standing with God because they believe or their faith is carrying them through. This makes faith a work, something again inside us. The creeds already warned against this tendency a long time ago. For example the Belgic Confession Article 23
However, we do not mean, properly speaking, that it is faith itself that justifies us-- for faith is only the instrument by which we embrace Christ, our righteousness.
But Jesus Christ is our righteousness in making available to us all his merits and all the holy works he has done for us and in our place. And faith is the instrument that keeps us in communion with him and with all his benefits.
This is just an example that is of subtle nature. But what about the modern therapeutic messages one gets from the pulpit? One can ask, is Christianity about victorious living?
This lack of appreciation for creeds is part of being a-historical (no need to study history). I am almost certain that when I pick any young people in church today, they would not be able to recite the Apostle's Creed. Today evangelicals/ pentecostals find unity and oneness with each other based on one's spiritual experience i.e being born again etc., rather than a common message. The a-historical mentality is really a modern worldly attitude found in today's society. Creeds are viewed traditional, religious, old and irrelevant.
There is a saying "those who do not remember the past are condemned to repeat it", specially the erroneous part or the bad part of history. The evangelical/ pentecostal should see their a-historical and a-creedal attitude not a strength but may well be a weakness, it is a shot in the foot too.