The context (including several more gems):
"Salvation through Christ and life in the church is a complex mystery in Acts. Christianity is acceptance of the message that Jesus is Lord and Christ and adherence to him in personal faith. But acceptance of Christ and his message is still only a beginning. This act leads necessarily to baptism into a community, where believers share life together in κοινωνία [fellowship]. Because the church is missionary, this fellowship is not introverted, but opens out to the world under a mandate to witness to Christ by preaching the word to others by word and deed. Faith leads to community, community to witness. The circle is completed when the believer, having accepted the word through the church, takes the word to others as a member of the church.
"After the resurrection, the word of God is embedded in the Christian community. It lives in the church in a community of life with the believers. In preaching the word, the believer is preaching his own life as lived in community, and the offer and challenge of faith is an offer of community. Luke sees the word so bound up with community life and witness that he can say "The word of God grew" when the church adds new members."- Jerome Kodell, “‘The Word of God grew’: The Ecclesial Tendency of Λόγος in Acts 1,7; 12,24; 19,20” Biblica 55 (1974): 505-519, here 518.