Matthew 5:48

You therefore shall be perfect, as your heavenly Father is perfect.”

The first thing to note here is that ‘you' is both plural (in contrast with much of what has gone before) and emphatic. It means ‘you band of disciples' (you new congregation of Israel), in contrast with all others. This idea of the completeness and ‘perfection' of the whole body particularly comes out in Ephesians 4:12. Those separated to God (His ‘saints' or ‘holy ones'), who are being taught by those appointed by God, are to be ‘perfected' for His service. And that will go on until ‘we all attain to the unity of the faith and the knowledge of the Son of God, to a ‘perfect' man, to the measure of the stature of the fullness of Christ'. This is the aim set before God's people as a whole. By this the Kingly Rule of Heaven will be manifested and they will be the light of the world. So while it applies to each, it also applies to all, and when one comes short he mars the whole body. In view of this it can therefore only indicate potential perfection rather than present perfection, the hope of what is to be striven for and finally achieved.

Here in the context of Matthew we may see this command statement as either closing off these few verses (Matthew 5:43) or as closing off this whole section (Matthew 5:17). If the former it has in mind the universal and all-embracing love of God described in Matthew 5:43. Their ‘perfection' or ‘completeness' will be revealed by their being ‘all embracing' in their love like God is. Those who fail to love all will not be ‘perfect' as their heavenly Father is, for He does love all, and they will thereby mar the whole body. Alternately it may be emphasising the need to fulfil all that is contained in the Law and the Prophets concerning God's Instruction, as in Matthew 5:17. In this case it has in mind the need to observe every last detail of God's Instruction (Matthew 5:19), thus being ‘like God Himself' by seeking to achieve the total fulfilment of His revealed will. That is why those who break one of the least of the commandments and teach men so will be called ‘least' in the Kingly Rule of Heaven (Matthew 5:19). They are a blot on the whole. For, as we will see below, being ‘perfect' is often linked with conforming to the whole will of God.

We may also see ‘you shall be' as indicating firstly what their aim must be, they are to be ‘perfect' in their loving and in their living as God is, and secondly as indicating what will in the end be the result of their being His disciples and totally committed to His will. They will become ‘perfect' in the fullest possible sense, for they will one day be like Christ, and will see Him as He is, which is why they are now to seek to purify themselves even as He is pure (1 John 3:2).

These two aspects of perfection come out if we consider other verses where the word is found. For the word translated ‘perfect' here is ‘teleios', which means ‘attainment of an end or aim, completeness, being all-embracing, being of full measure, being fully grown, mature, and up to standard, being perfect'. Thus in Matthew 19:21 the rich young man would be ‘perfect' if he sold all and followed Jesus. He would be rounding off his present high standard and ‘making it complete'. He would be filling up what was lacking in his attitude by getting rid from his make-up of the love of wealth and becoming someone totally dedicated to Jesus, seeking first the Kingly Rule of God and His righteousness (Matthew 6:33). It was the one thing lacking in him. Once he had done that his dedication to God would be complete. In Romans 12:2 Paul speaks of the need for us to offer ourselves as living sacrifices, holy and acceptable to God, for that is what will constitute our true spiritual worship and priestly service. And this will be achieved by our not being conformed to this world, but by our being transformed by the renewal of our minds, that we may prove what is the good, acceptable and  perfect  will of God. Both Matthew 19:21 and Romans 12:2 are indicating that in order for us to be ‘ perfect ' and be matched with the perfect will of God there must be total dedication and separation from the world and its aims and follies, and total commitment to following Jesus, with minds and wills that are open to the working of God. And here in Matthew Jesus expected that of the whole band of disciples. They were to be team players in the game of love.

In 1 Corinthians 2:6 Paul writes of ‘speaking wisdom among those who are  perfect ', that is among those who are so dedicated and in tune with God that their minds are spiritually attuned to receive spiritual truth (1 Corinthians 2:12). In 1 Corinthians 14:20 being ‘ perfect ' is contrasted with being like a child, ‘in malice be children, but in how you think (in mind) be perfect'. They are not to be developed in malice, but they are to be developed and fully grown in how they think. It therefore means fully grown spiritually, spiritually adult and mature. In Ephesians 4:13 Paul says, ‘until we all attain to the unity of the faith and of the knowledge of the Son of God to a  perfect  man, to the measure of the stature of the fullness of Christ'. Here what we should aim to be is described and ‘perfection' indicates becoming like Christ in all His fullness through believing in Him and knowing Him more and more, something to be eventually achieved by the whole church, even though it has not yet been achieved. In Philippians 3:12; Philippians 3:15 Paul recognises that he is not already  perfect  (cognate verb), that is fully fitted for resurrection, and that is because he does not as yet sufficiently know Christ and the power of His resurrection, and the fellowship of His sufferings, being conformed to His death. And yet he does class himself among those who are ‘ perfect ', that is, are morally and spiritually mature, who should therefore be pressing on towards the goal, towards the prize of the high calling of God in Christ Jesus (when full perfection will be theirs). In Colossians 1:28 it is Paul's aim, by admonishment and teaching in all wisdom, to present every man  perfect  in Christ Jesus. In Colossians 4:12 Epaphras is depicted as striving in his prayers for the Colossians, praying that they might stand  perfect  and fully assured in all the will of God. He longs for them to be people of full faith. In Hebrews 5:14 milk is for babes but solid food is for  perfect, that is, full grown men, but full grown men who have, by reason of use, had their senses exercised to discern between good and evil. In James 3:2 the man who can control his tongue demonstrates that he is a  perfect man, able to control his whole body. He is fully mature and in total control. Thus ‘perfection' firstly has in mind full growth and maturity in spiritual and moral experience, and secondly becoming like God Himself in the fullness of spiritual and moral experience.

Coming back to Matthew then Jesus is not speaking of the attainment of individual disciples, but of the attainment of the whole. He sets before the whole band what their goal together must be, although, of course, in the fulfilment of that goal each individual must play his part. Thus perfection is the goal and the end, not achievable (except theoretically) immediately, but to be attained in the end. It is what his band of disciples, and later His newly founded ‘congregation' (Matthew 16:18; Matthew 18:17), are to be aiming for. And it must be achieved in terms of what He has been saying, and especially in their revealing of universal love, that is, of love to all, in the same way as God's beneficence is revealed towards all.

By this they are to reveal the all round perfection of their Father. And they will do so by the complete fulfilling of His perfect Law (Instruction), because in that Law is revealed His very nature. In Leviticus 11:44; Leviticus 19:2; Leviticus 20:26 God had required His whole people to be holy as He was holy, separated from sin and set apart so as to reveal His all round goodness, and therefore as having to keep themselves from all that was defiling. And that had included love for their neighbour and for the foreigners among them (Leviticus 19:18; Leviticus 19:34). That still remained true. They were to be in the world but not of the world. But now they were above all to reveal this by the heavenly love that they showed for all the world, in the same way as their Father in Heaven did. While separated from the world as citizens of Heaven (Philippians 3:20) under the Kingly Rule of Heaven, they were to embrace all who were in the world within the embrace of their love. And by this they would as a whole become complete men and women, developing into full Christlikeness, ‘to the measure of the stature of the fullness of Christ' (Ephesians 4:13), with each one being an essential part of the whole.