Imagine a compound in which there were only Christians and never any contact with the outside world. Does that sound good? It is not. While it may be comfortable, and while it may be a foretaste of eternity, it’s not right. The Savior prayed,
15 I do not ask that you take them out of the world, but that you keep them from the evil one.
16 They are not of the world, just as I am not of the world.
17 Sanctify them in the truth; your word is truth.
18 As you sent me into the world, so I have sent them into the world. – John 17:15-18
The Savior did not ask that the Father would remove His disciples from the world. On the contrary, He sent them into it, just as His Father sent Him into it, to seek and save the lost.
The disciples weren’t meant to be isolated from the world, and neither are we. Now mind you, we are not of the world, in the sense that we don’t ultimately belong here, nor should we rebel against God as the world does, but we are sent into the world to preach the gospel to all of creation.
The reason why we are not teleported to heaven at the moment of conversion is that there is work to do. The Lord is saving a people for Himself, and He uses people like us to accomplish His purposes through the message of the gospel and by His power.
So, even as we long for heaven, let us not forsake our time here in the world.