“But speaking the truth in love, may grow up into him in all things, which is the head, even Christ:”
Ephesians 4:15

He says when we behold the word, we are changed, he also said we grow into him when we speak the word in love:
“speaking the truth in love, may grow up into him”
Jesus made clear what truth is:
“Sanctify them through thy truth: thy word is truth.” John 17:17
And so he defines how we live our lives— we dwell in and express love and we speak the word always irrespective of the conditions, just like Jesus:
“If ye keep my commandments, ye shall abide in my love; even as I have kept my Father’s commandments, and abide in his love.” John 15:10
This is our sanctification; this is what separates us from the rest of the world- that his gracious words are always found on our lips and seen in our deeds.
He says when we do this, we would grow up into him in all things, simply- keep his saying concerning all things, when it comes to, speak the words of the one who owns, lives in and propels you, just like Jesus:
“Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works.” John 14:10

Bible Reading Plan: Ishiah 54 and Leviticus 19