(17) Pray without ceasing.--Theophylact well says, "This shows the way to 'rejoice always'--to wit, incessant prayer and eucharist, for he that has accustomed himself to hold converse with God, and to give thanks to Him over everything that happens as happening well, will evidently have unbroken joy." Though a man cannot be incessantly praying in words, the mind may be held continuously in an attitude of prayer, even in sleep (Song of Solomon 5:2).

Verse 17. - Pray without ceasing. The means of promoting religious joy is prayer. This prayer is to be "without ceasing," implying constancy (Colossians 4:2) and perseverance (Romans 12:12; Ephesians 6:18; Luke 18:1). This is not a mere precept "capable of fulfillment in idea, rather than in fact" (Jowett); but it is an exhortation to live in a devotional frame of mind. It is impossible to be always on our bended knees, but we may be in the spirit of prayer when engaged in the duties of our earthly calling. Prayer may be without ceasing in the heart which is full of the presence of God, and evermore communing with him.

5:16-22 We are to rejoice in creature-comforts, as if we rejoiced not, and must not expect to live many years, and rejoice in them all; but if we do rejoice in God, we may do that evermore. A truly religious life is a life of constant joy. And we should rejoice more, if we prayed more. Prayer will help forward all lawful business, and every good work. If we pray without ceasing, we shall not want matter for thanksgiving in every thing. We shall see cause to give thanks for sparing and preventing, for common and uncommon, past and present, temporal and spiritual mercies. Not only for prosperous and pleasing, but also for afflicting providences, for chastisements and corrections; for God designs all for our good, though we at present see not how they tend to it. Quench not the Spirit. Christians are said to be baptized with the Holy Ghost and with fire. He worketh as fire, by enlightening, enlivening, and purifying the souls of men. As fire is put out by taking away fuel, and as it is quenched by pouring water, or putting a great deal of earth upon it; so we must be careful not to quench the Holy Spirit, by indulging carnal lusts and affections, minding only earthly things. Believers often hinder their growth in grace, by not giving themselves up to the spiritual affections raised in their hearts by the Holy Spirit. By prophesyings, here understand the preaching of the word, the interpreting and applying the Scriptures. We must not despise preaching, though it is plain, and we are told no more than what we knew before. We must search the Scriptures. And proving all things must be to hold fast that which is good. We should abstain from sin, and whatever looks like sin, leads to it, and borders upon it. He who is not shy of the appearances of sin, who shuns not the occasions of it, and who avoids not the temptations and approaches to it, will not long keep from doing sin.Pray without ceasing. Not that saints should be always on their knees, or ever lifting up their hands, and vocally calling upon God; this is not required of them, and would clash with, and break in upon other parts of religious worship, and the duties of civil life, which are to be attended to, as well as this, and besides would be impracticable; for however willing a spiritual man might be to be engaged in this work always, yet the flesh is weak, and would not be able to bear it; and it requires food and drink, sleep and rest, for its refreshment and support; for all which there must be time allowed, as well as for other actions of animal life, and the business of a man's calling. But the meaning is, that believers should be daily, and often found in the performance of this duty; for as their wants daily return upon them, and they are called to fresh service, and further trials and exercises, they have need of more grace, strength, and assistance, and therefore should daily pray for it; and besides certain times both in the closet, and in the family, in which they should attend the throne of grace, there is such a thing as mental prayer, praying in the heart, private ejaculations of the soul, which may be sent up to heaven, while a man is engaged in the affairs of life. The Ethiopic version renders the words, "pray frequently"; do not leave off praying, or cease from it through the prevalence of sin, the temptations of Satan, or through discouragement, because an answer is not immediately had, or through carelessness and negligence, but continue in it, and be often at it; see Luke 18:1. These words are opposed to the practice of such, who either pray not at all, or, having used it, have left it off, or who only pray in a time of trouble and distress, and bear hard on those who think they should not pray but when under the influences of the Spirit, and when his graces are in a lively exercise: the reason for this rule of praying with frequency and constancy is, because the saints are always needy, they are always in want of mercies of one kind or another, and therefore should continually go to the throne of grace, and there ask for grace and mercy to help them in time of need.