In two ways

 "In two ways, we are one: in our essence, and in our character.

In our essence, we are all one soul, with one source.
In our character, we are all complementary to each other, none of us complete, each one contributing what the other lacks, each one adding his touch of perfection to his fellow. Like a massive jigsaw puzzle, we fit together to make a single perfect whole.
None of us is perfect without all the rest of us.
And all the rest of us are incomplete when a single individual is missing."

Rabbi Tzvi Freeman
Artwork - Then the Lord told Moses, “Go down and prepare the people for my arrival. (Exodus 19: 10 - 11)