In this one verse, we see a formula which aids in our spiritual maturity.
Continual prayer + remaining alert + giving thanks creates an incubator effect in the believer who is maturing spiritually.
“Christianity is not about learning how to live within the lines; Christianity is about the joy of coloring.” (Yaconelli)
Continual prayer is practicing God's presence on a daily basis, it is not about our performance or garnering God's attention. It is hard work to practice God's presence continually, but if we see it as an utter necessity, we will develop this habit more and more as we walk with the Lord.
Maintaining healthy fellowship with anyone requires communication. It is a determined mindset that causes us to be "on line" with one another. And, it is no different with God. Being "on line" with the Lord is a conscious decision that we make every day.
The heart attitude of praying without ceasing is an ever-open heart to the Lord’s presence. And, when we exercise His presence through an unending type of prayer, we position ourselves to experience, in a greater degree, the life Jesus died to give us. The Bible calls it "eternal life", life with the touch of eternity upon it.
The second part of this formula is "keeping alert" which is "gregorao" in the Greek. Gregorao means to be cautious, give attention and to be on guard. Most think this admonition is here to alert us to the enemies presence. It is not. We are to be alert to Jesus' presence and activity in our lives.
My wife and I recently rescued a dog. Today, I took her for a ride. I noticed that when I got out of the car to put gas in the tank, this little dog did not take her eyes of me. She ran from one side of the car to the other just so she could keep her eyes on me. It was at that point that I remembered this verse. It could read "keep your eyes on me."
Finally, the third part to this formula is "always thanking God." It is natural that Paul would remind us to be thankful in light of the activity of God in our lives.
I have discovered along my journey the more I choose to be thankful, the more I have to make me more thankful. When I foster grateful heart, I am discovering that my hearts is often like a magnet sweeping over my day, collecting reasons for which I am grateful.