13 Having therefore learned all these things, even if we be in sins, and unworthy of receiving, let us not despair; knowing, that by assiduity of soul we shall be able to become worthy of the request. Even if we be unaided by advocate and destitute, let us not faint; knowing that it is a strong advocacy— the coming to God one's self by one's self with much eagerness. Even if he delay and defer with respect to the giving, let us not be dispirited; having learned that the putting it off and delay is a sure proof of caring and love for mankind.
If we have thus persuaded ourselves; and with a soul deeply pained and fervent, and thoroughly roused purpose; and such as that with which the woman of Chanaan approached, we too come to him, even if we be dogs; even if we have done anything whatever dreadful; we shall both rebut our own crimes, and obtain so great liberty of speech as also to be advocates for others; in the way in which also this woman of Chanaan not only herself enjoyed liberty of speech and ten thousand encomiums but had power to snatch her dear daughter out of her intolerable sufferings.
For nothing— nothing is more powerful than prayer when fervent and genuine. This both disperses present dangers, and rescues from the penalties which take place at that hour. That therefore we may both complete our passage through the present life with ease, and depart there with confidence, with much zeal and eagerness let us perform this perpetually. For thus shall we be able both to attain the good things which are laid up, and to enjoy those excellent hopes; which God grant that we may all attain; by the grace and loving kindness and compassion of our Lord Jesus Christ— with whom to the Father together with the Holy Spirit be glory, honour, dominion, to the ages of the ages. Amen.
Source: Homily Concerning "Lowliness of Mind" (New Advent)