Here's one of the many beautiful developments in Scripture
1. God's Word runs the universe. From creation to the end, as 2 Samuel 22:31says, "The Word of the Lord proves True." God says it, and there is it! (Gen 1:3) God's Word runs everything; God's Word will be established. God's Word is always trustworthy.
2. God's Word enters the mouth of God's King. Psalm 2:7 describes God's decree over God's King. But then the Psalm goes on to show that we serve God's decree by serving God's King. (vv. 11-12)
3. But we see kings in Scripture--God's kings, Israelite kings--who are not trustworthy and don't seem to be worth obeying. For example, the very first one, King Saul. Or King David in 2 Samuel 11-12. Or most of the other kings in the Old Testament. This creates Messianic-Tension; that is, the longing for God to fulfill His Kingly, Genesis 3:15, promise.
4. So the prophetic prayer is shaped into this hope: for the Word of the Lord to come like a king: to be over all and involved in every area of our lives. And for our king to be like God's Word: always trustworthy.
5. We arrive at Jesus: "...The Word [by which all was created, who is Himself God] became flesh and dwelt among us." (John 1:14) Now, in Jesus, our King IS God's Word and God's Word IS our King.
6. So now, "Let the Word of the King/Christ dwell in you richly." (Col 3:15) Paul recognizes that this merger has happened, in fulfillment of God's promises and the Old Testament prayers.
There is no hunting for God's Word apart from Jesus. We have in Him the fully reliable, authoritative, Word of God. And there is no serving Jesus versus obeying God's Word. The Word is about Jesus; Jesus is the fulfillment and embodiment of God's Word.
8. Take Away: We must submit our lives fully and completely to Jesus. He is the Word of God. He is totally authoritative. Also, we can entrust our lives fully and completely to Jesus. The Word of God is in Him. He is fully reliable. So if you're at a cross-roads or if you're in a bind, Jesus is the One you want. And Jesus is the One you have.