The word 'prayer' has many meanings. Three of the primary meanings are fervent request, liturgy, and acts of communion with God. Tertullian concentrated on #2, with mention of #1. Origen moved toward #3. Most mention of prayer in the Bible is refers to definition #1. However, when Paul exhorts us to pray continuously, he is presumably firmly in the #3 camp.
The difficulty with 'praying continuously' is that it is, well, difficult. Most of us have difficulty maintaining focus in verbal prayers, let alone maintaining continuous fellowship with God. Nevertheless, controlling the thoughts and the will seems to be a fundamental element in Jesus' teaching, and "recollecting" yourself into God's presences is a key element of teaching on prayer.
This month's classic on prayer is the Conferences of John Cassian. Cassian (360-435) visited the "desert fathers" in monasteries and hermitages in the desert in Egypt, where Christians had fled from Roman persecution in the third century. The Conferences consists of teachings he heard there and brought back to the Western church.
His method involves repeating Psalm 70:1 as often as possible: "O God, make speed to save me: O Lord, make haste to help me." Abbot Isaac says that this verse can be "adapted to every condition, and all assaults. Since it contains an invocation of God against every danger, it contains humble and pious confession, it contains the watchfulness of anxiety and continual fear, it contains the thought of one's own weakness, confidence in the answer, and the assurance of a present and ever ready help."
Abbot Isaac goes on to recommend repeating the verse when in despair or temptation or success or delight. It should be repeated when in want or prosperous. It should be said when in danger or covetousness or gloominess or raging passion or coldness or humility or simplicity or joy. By the constant repetition of this verse, according to Abbot Isaac, you will be recollected and strengthened and brought into God’s presence.
Director of the CCEL