“. . . and pray [also] for one another . . . The earnest (heartfelt, continued) prayer of a righteous man makes tremendous power available [dynamic in its working].” James 5:16 (AMP)
“. . . and pray for each other . . . The prayer of a person living right with God is something powerful to be reckoned with.” James 5:16 MSG) 
“. . . and pray for each other . . . The earnest prayer of a righteous person has great power and wonderful results.” James 5:16 (NLT)

This Scripture, primarily used relative to healing and health, clearly describes the power of prayer and, far more, succinctly relays the result of fervent prayer.
 
fer•vent  –  1 Ardent in feeling; fervid
 
ar•dent  –  1 Vehement in emotion or action; passionate; zealous
 
ve•he•ment  –  1 with great force or energy; energetic
 
All covered by the blood of Jesus the Anointed One and His Anointing are righteous because the Blood has put each (who believe and confess Him) in right standing with God the Father. However, it is not necessarily true that every individual reconciled unto the Family of GOD prays in fervent fashion, which pertains neither to volume nor to length. Accuracy is key in terms of whether the person praying is speaking belief in what GOD says, which requires a critical ear rather than a critical tongue. For example: Is the person praying speaking belief? Do their words line up with what GOD says about His sons & daughters? Such emphasizes the importance of developing a personal relationship with GOD; becoming familiar with His character through the WORD by revelation of the information therein by the Teaching of the Holy Spirit. Now, the LORD comes by invitation. However, the devil and his cohorts will trespass which is why we were given the sacred ministry-of-authority in the Name above all names. Therefore, when the wicked one attempted to involve himself in my affairs via a recent administrative decision pertaining to my workplace, I entered into a Prayer of Agreement (Matthew 18:19), for the first time ever with a Sister-in-Christ who prays both fervently and in keeping with the WORD. Colleagues across the board were perturbed and expressed their opinion as to what they perceived as nonsensical. Ah, but GOD! . . . On the same morning that it was to occur, the person who initiated the decision reversed it! All praises be to the King of kings and the LORD Our GOD He is wonderful.