The disciples spent three years in the presence of Jesus: God in the flesh. They sat under His teaching and lived with Him daily—studying His perfection. And yet, even though they had come to believe that He was the Christ, on their last night together, they ran into a wall of fear and unbelief.
All of us who believe in Jesus have what-I-call “pockets” of unbelief! In fact, it is one of Satan’s primary strategies to keep our pockets full of unbelief—“Satan, the god of this evil world, has blinded the minds of the unbelieving, so they are unable to see the glorious light of the Good News” (2 Cor. 4:4a). Satan wants to keep "believers" from fully believing!
When Jesus encountered a boy possessed by a spirit, the boy’s father asked Jesus “Do something if you can." Noting the father’s doubt, Jesus said “What do you mean, `If I can'? Anything is possible if a person believes." And the father exclaimed, “I do believe; help me overcome my unbelief” (Mark 9:22-24 NLT). And here is the real problem we “believers” deal with. We do believe but, still, we have doubts—pockets of unbelief. In these areas of unbelief we should pray “Lord, help me in my unbelief.” Though the Ephesian Christians were already great believers, still Paul prayed for God to open their eyes (unblind them) and to give them revelation in order to believe, even more, in the incredible greatness of God’s power (1:19).