The Seventy (Two) Return (10:17-20).
The return of the disciples, rejoicing in their being able to cast out evil spirits in Jesus' name, leads on to Jesus confirmation of the defeat of Satan and of the fact that He has given them power over all Satanic forces so that they need not be afraid of them. But He then stresses to them that they should recognise that what really matters is not these passing achievements. What matters is that their names are written in Heaven, that they are citizens under the Kingly Rule of God. That is the greatest privilege of all.
Analysis.
a The seventy two returned with joy, saying, “Lord, even the demons are subject to us in Your name (Luke 10:17).
b He said to them, “I beheld Satan fallen as lightning from heaven” (Luke 10:18).
b “Behold, I have given you authority to tread upon serpents and scorpions, and over all the power of the enemy, and nothing shall in any wise hurt you” (Luke 10:19).
a “Nevertheless in this rejoice not, that the spirits are subject to you, but rejoice that your names are written in heaven” (Luke 10:20).
Note how in ‘a' they rejoice because the spirits are subject to them, and in the parallel Jesus refers to this but points out that what is more important is that they are citizens of Heaven. In ‘b' He refers to the defeat of Satan of which he has been a witness, and in the parallel confirms that that defeat renders them secure from all his powers.