noun
unity
YOO-nuh-tee/ˈjuːnəti/
The state of being joined together as one harmonious whole.
The woven threads gain unity as one strong fabric.

Etymology
The idea of “oneness” extended to the harmonious combination of parts: distinct elements form a single whole through being joined together.
In context
the two become one they don't become the same but they do become one why because the Trinity is Unified the Trinity only operates in unity