“I do not ask that you take them out of the world, but that you keep them from the evil one. They are not of the world, just as I am not of the world. Sanctify them in the truth; your word is truth. As you sent me into the world, so I have sent them into the world. And for their sake I consecrate myself, that they also may be sanctified in truth.
John 17:15-19
If the single aim of salvation was heaven alone, why would we not be taken to glory at the moment of conversion? Sanctification is the ongoing work of the Spirit of God in our hearts and lives making us grow up into maturity, growing in us conformity to the image of Christ. There are no shortcuts to maturity - spiritual or otherwise. And perhaps the real gift to the disciples - and us - is not being removed from the pain of the world, the suffering in which sanctification can be accomplished - but being kept by God, and kept from the evil one (Psalm 121:5). But this saving, keeping, and sanctifying is not just for ourselves but is wrought in us to send us out to make disciples - everywhere.