Peter said, "[We] are kept by the power of God through faith unto salvation ready to be revealed in the last time" (1 Peter 1:5). I see in this a prophecy that in these last days, God is once more going to reveal his keeping power to his people.
Christ prayed to the Father concerning his disciples: "While I was with them in the world, I kept them in thy name: those that thou gavest me I have kept, and none of them is lost" (John 17:12). The disciples did not keep themselves in the will of God, they were kept by a mighty power outside of themselves. They could not have made it a single day without Christ's keeping power.
What a glorious prayer Christ prayed on our behalf: "I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil" (John 17:15).
In the Greek, the work kept is very expressive. As used in 1 Peter 1:5, it means:
To establish a military outpost.
To guard, hem in, protect with a garrison.
To establish a fortress with a full military line, with full military apparatus.
To discern the enemy far in advance and protect from danger.
Not only is the Lord a strong tower, but he establishes in us a military outpost, manned by a fully-equipped army. We actually become a powerful military outpost with armies of soldiers, horses, and chariots ready for combat, and with a sentinel that sees the oncoming enemy far in advance.
Jesus prayed, "Keep them from the evil...." The Greek word for keep means:
Deliverance from the effect or influence of anything bad, evil, grievous, harmful, lewd, malicious, or wicked.
Deliverance from Satan himself and all that is corrupt or diseased.
Put it all together and it seems almost too good to believe. We are God's military outpost, protected by a fully-equipped spiritual army of innumerable horses, chariots, and soldiers in full battle array completely informed of every enemy plan and device—wholly defended against Satan and all the evil powers in the universe. Now maybe we can understand what the Scripture means when it says, "Greater is he that is in you, than he that is in the world" (1 John 4:4).