The Anathemas of the Second Council of Constantinople, Number 1.
Here's anathema number 1:
I. If anyone does not confess that the Father and the Son and the Holy Spirit are one nature or essence, one power or authority, worshipped as a trinity of the same essence, one deity in three hypostases** or persons, let him be anathema. For there is one God and Father, of whom are all things, and one Lord Jesus Christ, through whom are all things, and one Holy Spirit, in whom are all things.
*An anathema is a strong denunciation of someone, or a declaration that they are heretical.
**Hypostases means persons.
Comments? Questions? What think ye?