Therefore you shall be perfect, just as your Father in heaven is perfect. (Matthew 5:48)
I approach the Sermon on the Mount, and Chapter Five in particular, with the following in mind: (1) The Beatitudes (Matthew 5:1-12) is who the Christian disciple is; (2) the remainder of Chapter Five (Matthew 5:13-5:47) is how the Christian disciple lives because of the who he is; and (3) Matthew 5:48 is the only final exam problem – does the Christian disciple conform to the image of Christ in is completeness, his teleios.
I would like to highlight how teleios in Matthew 5:48 is applied by various commentators to bring to light what perfection should mean to the disciple.
The Annotated Bible has the following to say about Matthew 5:48: The standard for the heirs of the kingdom is then His own moral perfection. But every child of God born anew has put before him the highest standard, which includes all that which the King here expounds and that is in possession of Himself, who is the true God and the eternal life, “to walk even as He walked.” “Be ye therefore perfect as your heavenly Father is perfect.”
Christ is the standard. God became a man and walked among us; and one reason he did was to be the standard for Christian living. The Beatitudes tell us we are to be like Jesus in character and the remainder of the Sermon tells us we are to be like Jesus in action.
What does this mean for the Christian disciple? Simply put it means he must live the Sermon each and every moment of his life. To live the life the disciple must study the Sermon, be the Beatitudes, and live the Sermon. This order is essential to living the teleios life: study, be, live. This all is worked out through the empowerment of the Holy Spirit. The disciple in his prayer life must seek to allow the Holy Spirit to work out the teleios life, because God is the standard, and only through Him can the perfect life be lived.