Security is so important to us. We lock our doors, set our alarms and have our video security systems. At night when our kids go out we worry about them. We give them cell phones so they get in touch with us, and we them.
We fear the unknown. We see craziness and wickedness all around us and worry about it touching us. We hedge against insecurity but we still feel insecure. The first century disciples faced insecurity, too. John writes his Revelation to people who are looking for security. They are facing persecution, even to the point of death. John seeks to embolden them. John writes the words of Jesus assuring them that, if they remain faithful, they will ultimately have security no adversary can breech (Rev. 21:1-5; 22:1-5).
When Jesus was leaving His disciples He told them to be of good cheer because He would overcome. John is telling us God did overcome. The adversary has been defeated. He may win today if we walk away and leave the secure zone, but ultimately he will not win.
And here is the good news for those first disciples. They would reign with God. That is good news for us too. Not only reign with God, but reign forever and ever. I cannot fathom that. Security forever and ever, no adversary. Just the presence of God in real and living color.
If security is secure in fellowship with God, why would anyone want to walk away?