Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ. For this I toil, struggling with all his energy that he powerfully works within me. – Colossians 1:28-29 (ESV)
You can get this same thought from Paul's prayer in vv. 9-14. This is what Paul was about. This was his purpose in life. And God supplied him with power to do it. May our purpose be the same as Paul's and may our power be from the Almighty!