“And have put on the new man, which is renewed in knowledge after the image of him that created him:”
King James Version (KJV)
3:10 In knowledge - The knowledge of God, his will, his word.
Col 3:10 Have put on the new [man]. Are born again and become new creatures in Christ (Joh 3:5). The new man has a new heart, new thoughts, a new life. Which is renewed in knowledge. With the new man there is a growth, a renewal. He grows continually in knowledge of Christ and into his image.