"the whole life and substance of the Church is in the Word of God"

"The gospel is, before bread and Baptism, the sole most certain and most noble mark [(symbolum)] of the Church, since [it is] by the gospel alone [that] it is conceived, formed, fed, produced, educated, led out to pasture, clothed, adorned, fortified, armed, conserved; in a word, the whole life and substance of the Church is in the Word of God, as Christ says:  'Man lives by every word that proceeds from the mouth of God.'"

"Euangelium enim prae pane et Baptismo unicum, certissimum et nobilissimum Ecclesiae symbolum est, cum per solum Euangelium concipiatur, formetur, alatur, generetur, educetur, pascatur, vestiatur, ornetur, roberetur, armetur, servetur, breviter, tota vita et substantia Ecclesiae est in verbo dei, sicut Christus dicit 'In omni verbo quod procedit de ore dei vivit homo.'"

     Martin Luther, Ad librum eximii magistri nostri Mag. Ambrosii Catharini, defensoris Silv. Prieratis acerrimi, responsio (1521), WA 7, 721 (705-778), ll. 9-14, quick-and-dirty translation mine.  I have not read around in this treatise, which has not yet (?) appeared in English, but is no. 1.42 on the Prospectus for the supplement to Luther's works.

"There is but one single utterance of God amplified throughout all the scriptures"

St. Augustine preaching, Morgan Library
& Museum M.1175 (1525/30), fol. 192r (cropped)

     "There is but one single utterance of God amplified throughout all the scriptures [(sit unus sermo dei in scripturis omnibus dilatatus)], dearly beloved. Through the mouths of many holy persons a single Word makes itself heard [(unum uerbum sonet)], that Word who, being God-with-God in the beginning, has no syllables, because he is not confined by time. Yet we should not find it surprising that to meet our weakness he descended to the discrete sounds we use [(propter infirmitatem nostram descendit ad particulas sonorum nostrorum)], for he also descended to take to himself the weakness of our human body."

     St. Augustine, En. Ps. 103.4.1 (Ennaratio 4.1 on Ps 103), as trans. Maria Boulding in WSA III/19, 167.  Latin from CAG, i.e. CCSL 40, 1521, ll. 1-7).  Image identified the Index of Medieval Art.

"no power of oureselues to helpe ourselues"

"O God, Who seest that in our own weakness we do continually fall, make, in thy mercy, the examples of thy holy children a mean whereby to renew in us the love of thyself. Through."

As trans. Divinum Officium (online).

"Deus, qui nos conspicis ex nostra infirmitate deficere, ad amorem tuum nos misericorditer per sanctorum tuorum exempla restaura. Per."

     The Anglican breviary containing the Divine office according to the general usages of the Western church put into English in accordance with the Book of common prayer (1955), E474 (Feast of St. Calixtus, 14 October, and possibly elsewhere in the Proper of the saints, Tridentine breviary and missal):

"O God, who seest that we have no power of ourselves to help ourselves:  we pray thee, that, by the examples of thy Saints; thou wouldest mercifully restore us to the perfect love of thee.  Through."

     This is no. 1876 in Corpus orationum, and no. 44 in Bruylants.  According to the former it is present in two strictly 8th-century sacramentaries, Prague (before 788, a "Gregorianized Gelasian" from Ratisbonne originally) and Gellonensis (late 8th), as well as a number of 8th/9th century (and later) manuscripts, too.

The collect for the Feast of St. Calixtus in the contemporary Liturgy of the hours is very different, and much less interesting.  Indeed, there does not seem to be a single occurrence of the clause "qui nos conspicis ex nostra infirmitate deficere" anywhere in the contemporary Liturgia horarum.

BCP 1549:  "we haue no power of oureselues to helpe ourselues", followed by a different text:  seconde Sonday [of Lent].

BCP 1662:  "we have no power of ourselves to help ourselves":  Second Sunday of Lent.

BCP 1979:  "no power in ourselves to help ourselves":  Third Sunday of Lent.