Building to me is a process. When I look back over my life I can see the progress God is making in me, but He is not finished with me. I love that children's song, "God's still working on me, to make me what I ought to be, it took Him just a day to make the moon & the stars, the sun & the earth and Jupiter & Mars. How loving and patient He must be, 'cause He's still working on me."
I will continue to build until it is impossible. The disciple Paul, is a perfect example of selflessly building up the Lord's church. His sacrificial love demonstates the way God will use a willing individual to build up the body of Christ.
Although there a missionaries all over the world, I do not need to leave home to build up the Lord's church. In your own local congregations there are countless opportunites to reach out the the elderly, the poor, the discouraged, the youth. Try them all and allow God to point you in the direction of the Great Mission of Building Up others.
So then, just as you received Christ Jesus as Lord, continue to live in him, rooted and built up in him, strengthened in the faith as you were taught, and overflowing with thankfulness.
As we are built up by others,
let us then reach out and build others up also!
It was He who gave some to be apostles, some to be prophets, some to be evangelists, and some to be pastors and teachers, to prepare God's people for works of service, so that the body of Christ may be built up until we all reach unity in the faith and in the knowledge of the Son of God and become mature, attaining to the whole measure of the fullness of Christ.