colossians 1:24-29
24 Now I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ's afflictions for the sake of his body, that is, the church, 25 of which I became a minister according to the stewardship from God that was given to me for you, to make the word of God fully known, 26 the mystery hidden for ages and generations but now revealed to his saints. 27 To them God chose to make known how great among the Gentiles are the riches of the glory of this mystery, which is Christ in you, the hope of glory. 28 Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ. 29 For this I toil, struggling with all his energy that he powerfully works within me.

God is a mystery to most people. They don't know much about Him, and what they do know they either made up, or learned from someone else who didn't know much about Him. As Christians, we have had this mystery revealed to us. This should result with us talking to people about Jesus, telling them and showing them what He's like, being missionaries in our culture, trying to shed some light on the mystery of who God is and what He has done for people. You are a missionary in your family, your workplace, your circle of friends. Paul was toiling to do that, struggling with all the energy that God gave Him. How seriously do we take the task of moving people closer to Jesus?