Written in heaven
Notwithstanding in this rejoice not, that the spirits are subject unto you: but rather rejoice, because your names are written in heaven. Luke 10:20
Our Lord is responding to the jubilant response of the seventy to the success they had experienced in their ministry: "And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name" (17). In the Gospels, we most often see demonic activity in terms of its effects upon people's physical being, like the woman (whom our Lord describes as a "daughter of Abraham") who had been bound by Satan for eighteen years by a physical condition causing her to be bent over so that she could not straighten up (Luke 13:16). To cast out demons was often then associated with physical relief from some condition afflicting the body but caused by evil spirits.
Hence we see why our Lord instructed his disciples not to rejoice that the demons were subject to them but rather that their names were written in heaven. It is because physical healing is only temporary at best if your name is not written in heaven. To relieve people of their physical infirmities is still of course a good thing - after all, our Lord sent his disciples out to do this and he himself freed many people from this aspect of demonic oppression - but it is not the best thing. The best thing is to have your name written in heaven.
What does that mean? I take this to mean that one's name has been written in the book of life of the Lamb slain from the foundation of the world (Rev. 13:8; cf. Rev. 3:5; 17:8; 20:12, 15; 21:27; Phil. 4:3). It means being among the elect chosen by the Father for eternal life (Eph. 1:4). To have your name written in heaven, therefore, is to be in possession of eternal life. That is what the disciples are to rejoice in.
We can see why, can't we? To have your name written in heaven means that heaven is your eternal home. It means that you will one day experience with unveiled face the glory of the Lord. It means that one day you will be eternally beyond the reach of sin and Satan. Physical healing on earth is great, but if we are not embraced in God's covenant mercies, it is only a temporary reprieve. Physical healing is good for us only insofar as it points us to this greater mercy of having your name written in heaven.
Can you know that your name is written in heaven? Yes (cf. Phil. 4:3). How? We know it, as the apostles knew it: has the gospel come to you not in word only but also in power and in the Holy Spirit and with much conviction (1 These. 1:4-5)? In other words, have you embraced Christ as Lord and Savior? Have you believed the gospel and repented of your sins? If so, the Bible tells us that we are saved - our names are written in heaven, not on the basis of our goodness but solely on the basis of God's mercy and grace in Christ. If that describes you this morning, regardless of whatever else you are facing, you have a reason to be glad and to rejoice. For if your name is written in heaven, no army of demons can erase it from the book of life. Your eternal happiness is both secure and assured. Yes, brothers and sisters, rejoice!