1 John 2:5-7

Amplified Bible

⁵ But whoever habitually keeps His word and obeys His precepts [and treasures His message in its entirety], in him the love of God has truly been perfected [it is completed and has reached maturity]. By this we know [for certain] that we are in Him: ⁶ whoever says he lives in Christ [that is, whoever says he has accepted Him as God and Savior] ought [as a moral obligation] to walk and conduct himself just as He walked and conducted Himself.

⁷ Beloved, I am not writing a new commandment to you, but an old commandment which you have had from the beginning; the old commandment is the message which you have heard [before from us].^(A)