They devoted themselves to the apostles' teaching and to the fellowship...
Fellowship is one of the great words in the Christian vocabulary. Think for a moment of a building going up and the bricklayer puts one brick on another and so on but suppose he didn't use cement. Very quickly the whole building would become unstable. The cement was vital to holding the building together. Fellowship is the cement that binds Christians together. If there is no real Christian fellowship in a congregation then that congregation is in deep trouble — it will collapse.
The Christians in the early church 'lived in a wonderful harmony' Acts 2:42 (The Message) and that is what we must want to have in our congregations too. There are many things that can prevent 'wonderful harmony' among Christians - for example, trying to bring ungodly things into the church or Christians taking part in ungodly practices with unbelievers.
But true fellowship can be seen when Christians love one another, help one another, pray for one another and with joy join with one another in the worship of our great God and Saviour Jesus Christ. There is also a bond of faith with Christians who may worship in other churches different from our own. True fellowship is grounded in our love and obedience to Jesus Christ.
Dear Lord, help me to love the fellowship of your people. Amen.