"If you would be perfect (teleios), go, sell what you have" (Mt 19:1)
The Greeks described a man as teleios when he had reached a certain standard, or had fulfilled certain requirements – such as, a student who had passed his exams; an athlete who had qualified for the games; an apprentice who had become a tradesman; and so on.
For a Christian, the standard required is simply this – surrender to the will of God. It is not so much a work as a condition; not what you do, but who you are; not what you have accomplished, but what you are becoming; not the labour of your hands, but the attitude of your will; not sacrifice, but obedience.
So for that rich young man, “perfection” involved giving away his wealth. But had he obeyed, that would have rendered him perfect only until Christ demanded another task from him. If he were then to disobey, his “perfection” would at once be lost, or at least marred. He could be “perfect” only so long as he obeyed each heavenly command (as it came to him) and continued to grow in the willingness and depth of his obedience.
So Jesus meant that the young man would become “perfect”, not when he was poor, but when he was obedient. Neither riches nor poverty are anything in the kingdom of God, but obedience is everything. The man whom God desires to be rich cannot be “perfect” if instead he chooses poverty; neither can the man be “perfect” who clings to wealth when God has commanded him to embrace poverty.
Perfection, therefore, does not necessarily require you either to gather riches or to give them up; nor does it depend upon any single or final act of obedience. Rather, we are required to maintain a daily attitude of surrender to the will of God, whatever that might be for each of us. All who are advancing in their obedience to God, who are growing in grace and maturity, who are pressing continually toward the prize that is set before them, may rightly call themselves “perfect”.
Obedience is a habit that grows. The pleasures that result from each new surrender to the will of God create an increasing eagerness to receive new and more challenging opportunities to serve God. That service also becomes more mature, deeper in wisdom, stronger in faith, wiser in performance, more joyful in fulfilment, more truly dependent upon the enabling grace of God.