There are probably millions of Christians who profess to be trinitarian but I wonder how many have taken the time to understand what the trinity doctrine really teaches? I would humbly suggest 'not too many'.
It also appears that most, because they understand the Scriptures to reveal the Father, Son and Holy Spirit as God, believe also that this is a very good reason for calling themselves trinitarian but this is not necessarily so. The trinity doctrine is far more involved (far more complex). So too are its implications. This is why this author, in this study, has sought to explain this teaching in an easy to understand manner.
First we need to understand what the trinity doctrine is and what it is not.