Therefore you shall be perfect, just as your Father in heaven is perfect. (Matthew 5:48)
Was there ever such a refinement of the most perfect law of the LORD as is here drawn? And where shall we look for the fulfilment of it but in the Lord JESUS himself? He indeed, and He only, observed it in the fullest extent of it. And therefore the close of the chapter is express to the purpose with an eye to him. Be ye perfect; that is, in the perfection of JESUS, for there is no other way of finding perfection but in him. What men talk of respecting sincerity for perfection, is a fancy formed nowhere but in their own brain. But as the members of the body partake in all that belongs to the head, so the members of CHRIST’S body are considered perfect in him. And when JESUS saith be ye perfect, he wills what he commands; his biddings are enablings. Be ye perfect in me. Hence the answer by the Prophet: Surely in the Lord have I righteousness and strength; Or as the apostle renders it, perfect in CHRIST JESUS.
He shall say, “Surely in the LORD I have righteousness and strength.” (Isaiah 45:24)
Him we preach, warning every man and teaching every man in all wisdom, that we may present every man perfect in Christ Jesus. (Colossians 1:28)
But of Him you are in Christ Jesus, who became for us wisdom from God – and righteousness and sanctification and redemption. (1 Corinthians 1:30)