Several discussions I've had recently regarding "Lex orandi, lex credendi" (Latin loosely translatable as "the law of prayer is the law of belief") have revealed that a faith community's practice is not separate-able from that community's faith. On the contrary, the practice is an outgrowth of the faith maintained in that community's tradition. Take for example church music, the church does not maintain one belief about the work of the Spirit in their midst and another belief about the music's work within people. Instead, it is more accurate to say that the belief that the church holds about music's work within people is an outgrowth of their belief about the Spirit's work among people.
This is going to be true in any number of church practices. That is particularly true in various rites and rituals associated with a tradition's faith confession. For example, I recently sought to imagine separating the form of one's baptism from the faith one has in baptism. It was my attempt to suggest that the faith associated with baptism superseded or made less relevant the manner in which one was baptized. However, this failed to take into account the manner in which one's faith is manifested in practice. Praxi fide (or "faith practice") acknowledges that one's practice grows out of not only the faith they have in Christ, but also the faith they hold in common with the believers they join. When one takes communion with a body of believers, or engages in worship practice with them, the practice itself is a confession of solidarity with the faith community they're in.
For this reason, imagine that one comes to a new church which has practices that differ from those that they have known. The Praxi fide of the new church is not separable into the faith the community holds to and the practice is represents. They are linked in such a way that the newcomer now has the opportunity to confess their common faith with the new church through undergoing a common practice. It would be evidence of the human tendency to slip toward a gnostic separation of matter and spirit (to which we all are susceptible) to attempt confessing common faith without embracing common practice. As Praxi fide is played out in each church tradition's unique context, believers do well (myself included) to remember that faith is not merely assented to in the mind, but it is practiced in the flesh, with the people of God around close by to express "Amen."