Augustine’s epistles have had a long-term influence on how Catholics pray, but with the specific material you provided, I cannot directly document how particular epistles shape contemporary prayer practice, because none of the supplied sources quote or analyze Augustine’s letters as a primary source of prayer-method today. What I can do is (1) show where Augustine’s influence on prayer is explicitly visible in your sources, and (2) explain how those themes commonly appear in Catholic prayer practice—especially interiority and Eucharistic prayer (the Church’s intercessory role and invocation of the Holy Spirit).

1) What Augustine’s epistles do to prayer practice (and what your sources don’t show)

To answer your question precisely, we would need sources that:

• identify particular epistles (letters) by Augustine,
• extract their teaching on prayer, and
• connect it to present-day Catholic prayer habits (liturgy, personal devotions, intercessory prayer, psalmody, spiritual direction, etc.).

Your provided material does not do that. So I cannot responsibly claim, for example, “Letter X specifically shaped practice Y.”

2) The Augustine-shaped prayer themes that are visible in your sources

A) Prayer as interior listening (“inner teacher”)

A concrete example of Augustine’s influence on contemporary prayer practice is the emphasis on interior listening and attentiveness to God within. In a message, Pope Leo XIV recalls Augustine’s spirituality—especially the idea that prayer is not merely external speech, but listening “through prayer, through silence, discernment and reflection,” and listening for the Holy Spirit “within our hearts,” described as “the inner teacher.”1

This is strongly consonant with common Catholic practices today, such as:

• silence before God (mental recollection),
• discernment in prayer (seeking God’s guidance),
• “interior” prayer forms (not only vocal prayer).

Pope Leo XIV also cites Augustine’s exhortation: “Do not have your heart in your ears, but your ears in your heart.”1

How this shapes prayer practice today: Catholics are encouraged to move from a purely outward orientation (hearing words, receiving information) to a more contemplative orientation (letting the Word and God’s voice be “heard” inwardly), which supports practices like examen-style reflection and contemplative reading/meditation.

B) Eucharistic prayer as Spirit-invoking intercession by the Church (with Augustinian resonance)

Another area where Augustine-shaped thought can be seen—though not specifically from his epistles in the provided sources—is in the theology and imagery surrounding the Eucharistic prayer, especially the Epiclesis (the invocation of the Holy Spirit) and the Church’s intercessory participation.

In the provided discussion of Eucharistic prayer theology, a key term—gemi tus columbae (“the groans of the dove”)—is noted as borrowed from St. Augustine (from De baptismo contra Donatistas).2 The same passage links this “groaning” imagery to the Church’s Eucharistic prayer seeking, through the Holy Spirit, a kind of participation in Christ’s mystery.2

Even more broadly, your sources describe the idea that in the Eucharistic liturgy:

• the Eucharistic prayer includes an element that functions as a Spirit-related “liturgical datum” (found in East and West), and
• the Roman Canon has a form that is interpreted as corresponding to this Spirit-invoking dynamic (the discussion turns on the Supplices te rogamus and the “holy Angel” language).3

How this shapes prayer practice today: Catholics praying the Eucharist (and those praying Eucharistic devotions that draw from the Mass) are formed to see the liturgy not as only a memorial “recitation,” but also as:

• intercession, and
• a prayer that calls upon the Holy Spirit for the transformation of bread and wine and for the grace of worthy reception.

That doesn’t prove a direct “epistle → practice” transmission, but it does show an Augustine-linked strand in how Catholics pray and understand the Eucharist.

C) Imprecatory prayer: not magical, but a trust in God’s justice

A different, but important, way prayer practice is shaped concerns what kinds of prayer are legitimate and how they work. Your supplied source from the Pontifical Biblical Commission explains that “imprecatory” prayer (prayers asking God to act against evil) does not function magically or mechanically; rather, it means entrusting to God the justice that only God can bring, renouncing personal vengeance, and trusting God to act in a way consistent with God’s nature.4

How this shapes prayer practice today: it guards Catholics against two distortions:

• treating imprecations as spells, or
• treating them as mere venting of hatred. Instead, Catholics are formed to pray difficult biblical language as a moral-spiritual act: entrusting, hoping, and asking for conversion and justice.4

Again, this is not shown as coming from Augustine’s epistles in the sources you provided, but it does reflect how the Church currently interprets biblical prayer forms that Augustine often engaged with broadly.

3) Bottom line

• With your provided sources, I can’t identify which Augustine epistles shaped which contemporary Catholic prayer practices.
• However, your sources do show Augustine’s influence on prayer in two identifiable ways:
  1. Interior listening and “inner teacher” spirituality (a pattern of prayer that fits modern Catholic contemplative/reflective habits).1
  2. Augustine-linked Eucharistic imagery and Spirit-invoking liturgical theology that supports how Catholics pray the Mass and relate Eucharistic devotion to the Holy Spirit.2 3
• Additionally, Church teaching on prayer language (like imprecation) clarifies how Catholics should pray—trusting God rather than using prayer magically.4

If you want the strictly “epistles-specific” answer, you’d need sources that quote Augustine’s letters (or a scholarly treatment of his correspondence on prayer) and then trace their reception into modern practice.