The First Commandment relates to the Absolute Oneness of God. Post Trinity Christians breach this, the most important of all the commandments.
Wibbo nowhere in the bible do we have the absolute one attributed to God, the Hebrew language of the day provided for such but it was never used. Maimonides a famous Jewish rabbi in countering Christianity made the point that although the absolute singularity of God is not found in the scrolls we must treat is as such and he went further in changing the word used for one in his translations.