Pray without ceasing - See the notes on Romans 12:12. The direction here may be fairly construed as meaning:
(1) That we are to be regular and constant in the observance of the stated seasons of prayer. We are to observe the duty of prayer in the closet, in the family, and in the assembly convened to call on the name of the Lord. We are not to allow this duty to be interrupted or intermitted by any trifling cause. We are so to act that it may be said we pray regularly in the closet, in the family, and at the usual seasons when the church prays to which we belong.
(2) we are to maintain an uninterrupted and constant spirit of prayer. We are to be in such a frame of mind as to be ready to pray publicly if requested; and when alone, to improve any moment of leisure which we may have when we feel ourselves strongly inclined to pray. That Christian is in a bad state of mind who has suffered himself, by attention to worldly cares, or by light conversation, or by gaiety and vanity, or by reading an improper book, or by eating or drinking too much, or by late hours at night among the thoughtless and the vain, to be brought into such a condition that he cannot engage in prayer with proper feelings. There has been evil done to the soul if it is not prepared for communion with God at all times, and if it would not find pleasure in approaching his holy throne.

Pray without ceasing - Ye are dependent on God for every good; without him ye can do nothing; feel that dependence at all times, and ye will always be in the spirit of prayer; and those who feel this spirit will, as frequently as possible, be found in the exercise of prayer.

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.

The Greek is, "Pray without intermission"; without allowing prayerless gaps to intervene between the times of prayer.

Pray without ceasing. See notes on Luke 18:1, and Ephesians 6:18.
In everything give thanks. Always be thankful for God's benefits, and always express your thanks. For scriptural examples, see Acts 27:35; 2-Corinthians 1:11; Acts 28:15; Ephesians 5:20.
This is the will of God. The three duties just named are probably comprehended.
Quench not the Spirit. Do not resist it, or counteract its influence by sensual lives. He does who disobeys the word of God, or refuses to follow the exhortations of those led by the Spirit, or who stifles his own conscience.
Despise not prophesyings. Inspired teachings. The prophets were specially inspired men in the early church. They were needed, because as yet it did not have the New Testament Scriptures for a guide. This inspired preaching must not be despised.
Prove all things. What was spoken they must put to the test, and all that stood the test, they must hold fast to. There were those who could "discern spirits" (1-Corinthians 12:10). There were also rules for testing (1-John 4:1-8).
Abstain from all appearance of evil. The meaning is to avoid evil in every form.