“You, therefore, must be perfect, as your heavenly Father is perfect” (Matthew 5:48).
A friend of mine was thinking about the meaning of Jesus telling us to be perfect, and he pointed out that the Greek word, teleios, used by Jesus in his teaching doesn’t imply “moral flawlessness” but rather a growing into what one is supposed to be. He then postulated that perhaps what Christ meant is that we are to ripen (like a fruit) to maturity.
I think there is a sense in which this is true for us, but I think teleios implies attaining the goal or purpose for which we exist. The sense of teleios/perfection is the completion of the process, whereas maturation and ripening refer to the ongoing process – not the goal, but a stage in the process toward the goal. The banana is going to continue to ripen, it doesn’t attain a stage of ripeness and then stop ripening. It will become overripe and then rotten.
I do think our Lord Jesus intended for us to mature, but that is to keep us moving toward the goal – the teleios/perfection, which He had in mind for us.
On the cross, Jesus says, “It is finished” (John 19:30) and uses the same word “teleios” but means the goal/purpose is accomplished or achieved or has been fulfulled.
Theologically we would say God is always teleios, he is not being perfected or moving toward perfection, unlike us his human creatures. God says, “I am who I am” (Exodus 3:14). God is the One Who Is, not one who is becoming, but being itself. We humans on the other hand are to attain the goal.
Going back to the notion that becoming perfect is like ripening fruit, we can ask, what is the goal of a banana? To ripen? No, ripening is the process by which the fruit provides for its seeds the opportunity to bring forth new life. Producing more fruit is the goal/teleios of any fruit. The purpose of a tree producing fruit is to produce more fruit! That is a spiritual truth which is supported by the ideas of evolution and natural selection.
In that sense our goal as Christians is not merely to mature, though this is what we are to do (see Ephesians 4:11-13). The real goal of the Christian life is to live in such a way as to bear fruit and thus plant more seeds to bring forth more fruit to the glory of God. We are to bear fruit in order to bring forth more life.
Jesus said, “I am the true vine, and my Father is the vinedresser. Every branch of mine that bears no fruit, he takes away, and every branch that does bear fruit he prunes, that it may bear more fruit. … By this my Father is glorified, that you bear much fruit, and so prove to be my disciples. … You did not choose me, but I chose you and appointed you that you should go and bear fruit and that your fruit should abide; so that whatever you ask the Father in my name, he may give it to you” (John 15:1-2,8,16).