"Ye are complete in Him," is the word to the believer. In the minds of many the difficulty in grasping the completeness of the life of Christ is the fact that the Christian life is progressive. You are to continually grow in grace and in the knowledge of the Lord; but to some this seems incompatible with being complete in Christ.
When Jesus Christ was on earth as a boy of twelve years old, He was perfect. But we read that He grew in wisdom and stature in the wisdom of God. Luke 2:52. Complete yet growing in grace and knowledge--perfect all the time! The plant is perfect at every stage of its growth. We admire the beauty of the plant when the leaves burst forth. It is perfect when the flowers bloom and perfect when the fruit appears. Yet it keeps growing!
It is not that you are to grow into grace but grow in in grace. You are not to get more and more into grace, but in grace you are to grow and increase in wisdom, complete in Him. The very statement of this fact implies that you are not complete in yourself. There is nothing good in you, but He is yours, and of His fulness have you received and grace over grace. His grace richly abounds and fills you."