I think the same thing applies among brethren when it comes to prayer. How many times have we committed to praying for someone, and promptly forgot to do so once we put the phone down, or the person has left our presence? It is a tragedy of our times that we are so often occupied with our own lives, that we can hardly make the time to invest in the spiritual well being of another, and especially, to pray for them. How many times have someone crossed our minds without our giving any thought to whether or not that person needed to be prayed for at that moment? It could be that the Holy Spirit allowed that intrusion in our thoughts so we could intercede on that person's behalf.
Praying one for the other is an integral part of Christian fellowship. James reminds us "...The prayer of a righteous man is powerful and effective" (5:16), and we see the Apostle Paul reassuring Philemon: "I thank my God, making mention of thee always in my prayers....That the communication of thy faith may become effectual by the acknowledging of every good thing which is in you in Christ Jesus" (Philemon 4, 6). We should be reminded that "the power of prayer is not the result of the person praying. Rather, the power resides in the God who is being prayed to." For God to act, He needs the cooperation of someone praying a prayer; making that request known. He most definitely listens to prayers, answers prayers, and moves in response to prayers.
Jesus spent a lot of time in prayer, and John recorded Him praying, "I pray for them: I pray not for the world, but for them which thou hast given me; for they are thine" (John 17:9). If He found it necessary to pray for the disciples then, and seeing He continues to intercede on our behalf (Romans 8:34), how much more are we to pray for one for the other?
I challenge you to think about this the next time you commit to pray for someone, or someone crosses your mind. Each one of us may be that link to another person's breakthrough. May God grant us sensitive hearts, and the conviction, to be obedient to that which the Holy Spirit has prompted us to do.