Brothers and sisters, we urge you to warn those who are lazy. Encourage those who are timid. Take tender care of those who are weak. Be patient with everyone. See that no one pays back evil for evil, but always try to do good to each other and to all people. Always be joyful. Never stop praying. Be thankful in all circumstances, for this is God’s will for you who belong to Christ Jesus. Do not stifle the Holy Spirit. Do not scoff at prophecies, but test everything that is said. Hold on to what is good. Stay away from every kind of evil (1 Thessalonians 5:14-22 NLT) [Emphasis added].

The apostle Paul exhorted new Christians to "pray constantly" (1 Thessalonians 5:17 RSV). As another translations puts it, "pray without ceasing" (KJV). The Greek text seems to have the same shade of meaning of the latter, so other translations give phrases like "pray continually" (NIV) and "never stop praying" (NLT) and "pray all the time" (MSG).

Realistically, it is impossible to "pray without ceasing" or "pray constantly" and still carry on the indispensable activities of daily life. This is especially so if we interpret "pray" to mean only talking to God and focusing only on Him, while we kneel, bow our heads, fold our hands, close our eyes, lift our hands to the heavens, or stand motionlessly in place.

This same problem occurred to Origen, the most outstanding Bible scholar, teacher, and preacher of the first half of the third century AD. He commented in his "Sermons on Samuel" that if this be the only meaning of "prayer," anyone who tries to "pray without ceasing" will die of starvation or dehydration because eating and drinking would interrupt the prayer. Paul's admonition would likewise forbid sleep and many other necessary daily activities.

So, how can anyone pray without stopping?

Did the Apostle who commanded constant and unceasing prayer demand the impossible?

Origen formulated a possible solution in his "Treatise on Prayer" written around AD 235. He further commented on it in his "Sermons on Samuel" five years later. The sermons inform us that a prayer is not interrupted by any action done in the service of God, nor by an act or word done or said in accordance with God's will. As long as we perform our daily activities to the glory of God then we are praying constantly.

The only way we can pray without ceasing is to constantly practice our Faith.
As proof, Origen cited the "Prayer of Hannah" (1 Samuel 2:1-10). The Bible applies the term "prayer" to all that Hannah spoke, even though not all of it is addressed to God. Sometimes she refers to God as "He" or by one of His titles, and otherwise in the third person. She even says:
Stop acting so proud and haughty!
Don't speak with such arrogance!
For the Lord is a God who knows what you have done;
he will judge your actions (1 Samuel 2:3 NLT).
Now this is not likely something a humble and devout human being would say to the Almighty, particularly in a prayer. Yet during her discourse, said Origen, all her thoughts and words were for the glory of God, which indicates that the Bible must mean something other than solemnly speaking to the Lord while stock still.

Prayer consists of all words and deeds spoken or performed in service to bring justice and everything done in obedience to God's commandments — something Christians should never cease doing (Romans 12:1-2). As long as we speak and act in accordance with the divine will, said Origen, we are praying. When we do or think unjustly or sin, we cease praying.

Origen expressed the same thought with fewer words at "On Prayer 12":

...if we count all good works and all obedience to God as part of prayer, a good person never stops praying. The only way we can pray without ceasing is to constantly practice our Faith.

This definition helps us understand that all we do to intentionally honor, bless, obey, and bring justice — to have God's "Kingdom come and God's will be done on earth as it is in heaven" (Matthew 6:10) — is part of our unceasing prayer to God!