If you have never heard of a nun who speaks in tongues, it is to the discredit of Christian denominations everywhere. When we criticize the devotional habits of other Christian communities, we undermine our spiritual siblings' individual relationships with God.
Yet how often has an Episcopalian ridiculed the liveliness of Evangelical worship services? On how many Sundays have married Protestant pastors intimated that the calling to cloistered living is a waste of time?
These criticisms cut off Christians from God. As James K. A. Smith writes in his book, Desiring the Kingdom (Cultural Liturgies): Worship, Worldview, and Cultural Formation,
Liturgies aim our love to different ends precisely by training our hearts through our bodies.
Smith is writing about liturgy, i.e. the collection of routines we repeat during organized religious gatherings. But I think the same is true of private devotional habits as well: the religious practices we repeat in the name of the Lord teach our hearts to love the God we have committed to serving.
Christian leaders of all stripes have encouraged members of their flock to connect with God in ways each finds effective, so long as these individuals acquire no false teachings in the process.
In his Sacrosanctum Concilium of 1963, Pope Paul VI notes:
Even in the liturgy, the Church has no wish to impose a rigid uniformity in matters which do not implicate the faith or the good of the whole community; rather does she respect and foster the genius and talents of the various races and peoples. Anything in these peoples' way of life which is not indissolubly bound up with superstition and error she studies with sympathy and, if possible, preserves intact.
Likewise Baptist Pastor John Piper, in a sermon discussing doctrinal disagreements rather than mere liturgical differences, observes,
The front door of the local church [should] be roughly the same size as the door to the universal body of Christ.
We are one Body of Christ, yet the Church consistently undermines its own parts to the detriment of the whole. By badmouthing unfamiliar devotional practices, we cast unnecessary doubt on the prior religious experiences men and women have had.
Of the people in my college fellowship who privately speak in tongues, many look back on their most fervent conversations with the Lord and wonder whether they were simply speaking gibberish. Because certain Christian communities mock all forms of speaking in tongues--often assuming the worst about the speaker's motivation--these men and women find themselves continually questioning some of their most intimate memories of God's blessing.
In addition to inspiring doubt, criticizing others' devotional practices often robs them of the tools they use to communicate with God. Last year, one of my friends at Harvard almost stopped praying altogether because her way of talking to God did not align with her Christian classmates' running list of ideal prayer conditions. What could be more damaging to a fellow sister's walk with God than to convince her that she isn't speaking with Him in quite the right way?
Finally, continually opposing other Christians' devotional habits creates a hierarchy of religious practice unique to each community and hostile to the greater Christian body. I would not be surprised if every Christian has felt ashamed of one spiritual habit or another when joining a new church community.
Whether it is listening to the wrong type of worship music in your car, conducting your daily devotional too late in the day, or wearing the wrong type of cross, so many of us experience castigation from our spiritual brothers and sisters. I am under no delusion that church exists to make us all comfortable, but neither should it become a forum for nitpicking others' devotional habits.
As you continue to interact with fellow brothers and sisters in Christ, consider exercising caution when criticizing devotional practices that are foreign or seem insufficient to another manner of worship. We risk much when we cast aspersions on the liturgies of Christian sects, since it is by these very acts that the men and women of God learn to love Him and prepare themselves for lives spend in His service.