Today's model of institutional church services falls short of producing what Paul is describing in Romans 14:17-19. Jesus' mission in proclaiming the Kingdom of God was not defined by programmed church services but by a lifestyle of goodness, peace and joy. Today, the focus of kingdom lifestyle is sorely distracted by activities, events, and memberships. The model of group singing (read: worship) followed by a musical performance and sermon with emotional altar calls prevent the focus of the kingdom lifestyle from emerging at an acceptable rate. In this passage Paul is directing gatherings to use a model that builds each other up in kingdom living. All that happens in the current model at best is the preacher may build up a congregation of listeners.
Following other writings by Paul we can assume the model that may best serve this purpose is one of interaction among all present. This allows each one to contribute their "gift" for the benefit of someone else and hopefully build them up in their lifestyle. The biblical model is clearly defined in this way. It is not top down (an American model) but more lateral.
Are there communities in Christendom that are willing to risk deconstructing a weak model for one that produces God's results in God's way?