Praying 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.
I'm on my last week of the Spiritual Warfare study that I've been going through by Chuck Lawless. Each week I have gone through six pieces of the armor of God, each requiring one to be faithful and obedient to Christ daily. Through this study I have realized that wearing the armor is never easy as it demands discipline and effort and requires much prayer.
Although prayer isn't a piece of the armor, it is a non-negotiable in winning spiritual battles. In his study, Lawless points out why Paul so strongly encouraged his readers to pray:
First, he understood that all believers battle against the Enemy. No follower of Jesus Christ is immune attack. If the Enemy was brazen enough to strike at Peter (Luke 22:31-32), Paul (2 Cor. 12:7), and Jesus Himself (Matt. 4:1-11), we shouldn't expect anything less.
Second, Paul knew the potential intensity of the attack. In 2 Corinthians 12, he used the word translated buffeting or tormenting to describe an attack from the Devil (v.7). The word he used literally means "to be slapped back and forth." The attack Paul faced was repeated, relentless, and ruthless. Paul knew the importance of believers praying for others who might face the same kind of assault.
Third, Paul expected believers to rejoice always. (1 Thess. 5:16), even when under attack from the Enemy (2 Cor. 12:8-10). He had learned from his own battles with his thorn in the flesh how to rejoice despite them. He pleaded with God to remove the thorn when he was being tormented, but God told him no. In the end, Paul learned that God's grace was sufficient for him, and he even rejoiced in "catastrophes, in persecutions, and in pressures" (v.10). Paul wanted other believers to rejoice, but such a response to difficulties seldom happens apart from others praying for us.
Fourth, Paul understood the brevity of life. He wrote the letter to the Ephesians from a jail cell, not knowing if he would live or die. He never wanted to miss an opportunity to glorify Christ, so he sought the prayers of others (Eph. 6:19-20).