That is partly true because a real Pentecostal is by definition an evangelist, whose faith is as infectious as the flu. The most important reason is that it is an oral religion. It is not defined by the abstract language that characterizes, for instance, Presbyterians or Catholics. Pentecostalism is communicated in stories, testimonies, and songs. Oral language is a much more global language than that of the universities or church declarations.
Oral tradition is flexible and can adapt itself to a variety of circumstances.
Certainly, but overall there is a basic evangelical consensus among Pentecostals. They are similar to the early church in this respect. Early Christians didn't have a formal, written confession of faith, as Presbyterians and others do today. They had the stories of Jesus. It was a very different way of achieving togetherness, and it was achieved through these oral forms.