To be a proper Christian, one professes a belief in Christ and is baptized with the Trinitarian formula (which is why Protestants are also Christians).
The problem is that baptism also initiates one into the Church, the body of Christ. With this comes a responsibility to study and understand the orthodox teachings of the Church, such as the incarnation, etc. Without a basic background into the history of the Early Church, a Christian can be easily fooled into wrong interpretations. For example, without knowing the teachings of the Early Church, a Christian can easily be duped into accepting ideas such as sola scriptura, a symbolic only interpretation of communion, not understanding apostolic succession, being opposed to the baptism of children, etc.
The truth is that whether Catholic or Protestant, religious education rarely progresses beyond a basic level. It never reaches Church history. It is very sad that adult Christians do not understand the faith on an adult level. Most cannot articulate the Trinity in a way that doesn't state a heresy of one sort or another -- not that this is easy LOL. Modern society tends to be anti-intellectual, and so a the necessity of a mature understanding is often scorned.
I can say that for me as an Evangelical, learning about the views of the Early Church Fathers made all the difference in the world. I had to swallow the hard truth that the early church was NOT Evangelical, but was, well, Catholic. It went down my throat like nails. But the truth is the truth.