Trinity~ fact or fiction? Serious replies only please!?

Please everyone without becoming hostile, can you BIBLICALLY give me an argument for and against the "trinity". I know that the word trinity is not in the Bible. I also would like to not see John 1:1 only because I have looked this up extensively and have found it interpreted as~~ the word was A god. In 5 or 6 different (non Jehovahs Witnesses) opinions. If you have old testament scripture to support or deny it that would be awesome! Thank you all!