True prayer is done in secret, but this does not rule out the fellowship of prayer altogether, however, clearly we may be aware of its dangers. In the last resort it is immaterial whether we pray in the open street or in the secrecy of our chambers, whether briefly or lengthily, in the Litany of the Church, or with the sigh of one who knows not what he should pray for. True prayer does not depend either on the individual or the whole body of the faithful, but solely upon the knowledge that our heavenly Father knows our needs. That makes God the sole object of our prayers, and frees us from a false confidence in our own prayerful efforts.
Dietrich Bonhoeffer, The Cost of Discipleship, p. 183