Speaking of Christ, Colossians 1:18 says
Col. 1:18 And he is the head of the body, the church. He is the beginning, the firstborn from the dead, that in everything he might be preeminent. (ESV)
(For more details on this verse, see HisWordMySword)
The context of this is that Christ is the Creator of all things (Col. 1:16). Not only that, but all things were made FOR Him. Thus, Christ has the right to everything in all of creation. He is the owner of all the things that we see around us. He is the owner of us. He is the owner of our time. He is the rightful owner of my car. He is the rightful owner of our houses. He is the rightful owner of your computer.
We belong to Him, because He made us for Himself. We belong to Him and everything that we have also belongs to Him.
And, the purpose for which He made everything was, as the verse above says, so that in everything (without exception) He would be preeminent (the first in importance and priority).
This truth is not something we naturally know. The ability to understand this is given by Him, through His Holy Spirit.
But understanding this is only the beginning. Once we grasp this truth, we need to apply it, with the gracious help of His Spirit. How can we do that?
The answer is simple, but difficult.
We need to begin to ask, about everything we do, “Am I doing this because Christ is my first priority?” For example, when I am spending “my” time watching some YouTube video, I need to reflect on the question “Am I spending the time God has given me doing this because Christ is my priority?” When I spend $10 on lunch, I need to ask “am I spending the $10 God has given me in this way because Christ is my priority?” When I say something to my wife, I need to ask “am I about to say this because Christ is the greatest priority in my life?”
To be sure, we are still not perfect, and we will still catch ourselves doing all kinds of things that do not reflect the truth that Christ is our priority. But, by the grace of God and the power of His Holy Spirit, as we ask these sorts of questions time and again, He will use them to redirect our actions, more and more, until our actions do demonstrate that in all things Christ is preeminent.