Today’s Catechism sections discuss praying without ceasing. Supporting material comes from the “Homily on First Thessalonians” by St. John Chrysostom.

IV. Perservering in Love

2742 "Pray constantly . . . always and for everything giving thanks in the name of our Lord Jesus Christ to God the Father."33 St. Paul adds, "Pray at all times in the Spirit, with all prayer and supplication. To that end keep alert with all perseverance making supplication for all the saints."34 For "we have not been commanded to work, to keep watch and to fast constantly, but it has been laid down that we are to pray without ceasing."35 This tireless fervor can come only from love. Against our dullness and laziness, the battle of prayer is that of humble, trusting, and persevering love. This love opens our hearts to three enlightening and life-giving facts of faith about prayer.

2743 It is always possible to pray: the time of the Christian is that of the risen Christ who is with us always, no matter what tempests may arise.36 Our time is in the hands of God:

It is possible to offer fervent prayer even while walking in public or strolling alone, or seated in your shop, . . . while buying or selling, . . . or even while cooking.37

2744 Prayer is a vital necessity. Proof from the contrary is no less convincing: if we do not allow the Spirit to lead us, we fall back into the slavery of sin.38 How can the Holy Spirit be our life if our heart is far from him?

Nothing is equal to prayer; for what is impossible it makes possible, what is difficult, easy.... For it is impossible, utterly impossible, for the man who prays eagerly and invokes God ceaselessly ever to sin.39
 
Those who pray are certainly saved; those who do not pray are certainly damned40

2745 Prayer and Christian life are inseparable, for they concern the same love and the same renunciation, proceeding from love; the same filial and loving conformity with the Father's plan of love; the same transforming union in the Holy Spirit who conforms us more and more to Christ Jesus; the same love for all men, the love with which Jesus has loved us. "Whatever you ask the Father in my name, he [will] give it to you. This I command you, to love one another."41

He "prays without ceasing" who unites prayer to works and good works to prayer. Only in this way can we consider as realizable the principle of praying without ceasing.42

IN BRIEF

2757 "Pray constantly" (⇒ 1 Thess 5:17). It is always possible to pray. It is even a vital necessity. Prayer and Christian life are inseparable.

In his “Homily on First Thessalonians” (10), St. John Chrysostom discusses prayer without ceasing.

Ver. 17, 18. Pray without ceasing; In every thing giving thanks: for this is the will of God.

Always to give thanks, this is a mark of a philosophic soul. Have you suffered any evil? But if you will, it is no evil. Give thanks to God, and the evil is changed into good. Say thou also as Job said, Blessed be the name of the Lord for ever. Job 1:21 For tell me, what such great thing have you suffered? Has disease befallen you? Yet it is nothing strange. For our body is mortal, and liable to suffer. Has a want of possessions overtaken you? But these also are things to be acquired, and again to be lost, and that abide here. But is it plots and false accusations of enemies? But it is not we that are injured by these, but they who are the authors of them. For the soul, he says, that sins, itself shall also die. Ezekiel 18:4 And he has not sinned who suffers the evil, but he who has done the evil.

Upon him therefore that is dead you ought not to take revenge, but to pray for him that you may deliver him from death. Do you not see how the bee dies upon the sting? By that animal God instructs us not to grieve our neighbors. For we ourselves receive death first. For by striking them perhaps we have pained them for a little time, but we ourselves shall not live any longer, even as that animal will not. And yet the Scripture commends it, saying that it is a worker, whose work kings and private men make use of for their health. Sirach 11:3 But this does not preserve it from dying, but it must needs perish. And if its other excellence does not deliver it when it does injury, much less will it us.

Footnotes

33  ⇒ 1 Thess 5:17; ⇒ Eph 5:20.
34 ⇒ Eph 6:18.
35 Evagrius Ponticus, Pract. 49: PG 40, 1245C.
36 Cf. ⇒ Mt 28:20; Lk 8:24[ETML:XC/].
37 St. John Chrysostom, Ecloga de oratione 2: PG 63, 585.
38 Cf. ⇒ Gal 5:16-25.
39 St. John Chrysostom, De Anna 4, 5: PG 54, 666.
40 St. Alphonsus Liguori, Del gran Mezzo della preghiera.
41 ⇒ Jn 15:16-17.
42 Origen, De orat. 12: PG 11, 452c.