doubledog said:
The bare minimum to proclaim you are a "Christian" is that you believe and follow the Nicaean creed.
Revised Version (381 AD).
...
I believe in one Lord Jesus Christ,
the Only Begotten Son of God,
born of the Father before all ages.
God from God, Light from Light,
true God from true God,
begotten, not made, consubstantial with the Father
...
If you do not believe then I do not know what you are but you are not a Christian.
I'm a Christian and I follow no creed; I follow the Bible, specifically, the Gospel. If both happen to be the same, so be it, but there's no "bare minimum" outside scripture. In fact, there's nothing outside scripture as far as the Gospel is concerned.
John 3:16 says most everything. What it MAY not cover is covered in John 14:6.
Don't add or subtract anything from the Gospel. Its all you need. Don't overthink this.