All the fullness (pleroma) of God (theotes) dwells somatikos, “bodily,” in the incarnate Son.   His body is the temple, filled with all the fullness of God (Colossians 2:9).

Paul immediately follows this declaration of Christ’s full deity with this: “and in Him you have been made complete (pleroo).”

“In” the Son are two realities: The fullness of the Father’s deity, and us.  Since we’re in the Son with the Father’s fullness, we become full.  In the Son with the pleroma of the Father, we are pleromized.