Paul encourages us to grow in knowledge.
This knowledge is mentioned twice in this chapter and is directed at two things: an increasing knowledge of God’s will and of God Himself. So, it is to be a matter of knowing what He would have us to do in life, what He desires, and what He has done. It is also an increasing knowledge of the character and being of God; He is calling for us to know Him.
The things you know influence the things you do, and one of the things that Paul would have us know are significant facts regarding the deity of Christ:
His magnificence and power are laid out, doing things that only the eternal, omnipotent God can do, setting Him up as the author and creator over all things (v. 15-16).
This is not something merely done in the past, but that same power presently consists and holds all things together. There is present sovereignty and all power consisting in one being (v. 17, 19).
This magnificent Son is also the one that is in charge of the church and the people within it. And it is the same Son that has done the work of reconciling them to Himself: Jesus, having accomplished it through the blood of the cross. The aim of this teaching is to ground the believers in the identity and work of the One who saved them (v. 23) so that they know He is the one to listen to (3:1-2).
Knowing that this is the Jesus who died for us ought to move us to diligently seek out His words, and to respect the words He has for us by following them. Disbelieving, ignoring, scoffing, disregarding, denouncing, not following, altering, or adjusting His words is not respecting this glorious Lord.