There is a reason why Satan is named Satan. The word means "accuser, adversary, opposer, obstructor, " in Hebrew. He opposed God in Heaven. He opposed God's first man and woman in the Garden. He opposed Job in the book bearing that name.
There is an "opposing" reason why the Son of God is named Immanuel in His incarnation. The word means "God with us," but the connotation is more than just that of presence. It includes and perhaps emphasizes a union by steadfast faithfulness and support. Isaiah 8:10 brings out this emphasis well: "Take counsel together, but it will come to nothing; speak a word, but it will not stand, for God is with us" (ESV). The counsel or word that will not stand is that of opposition, the plans laid for the destruction or conquest of God's people. But these plans are thwarted because "God is with us," that is, God is for us.
The importance of Jesus Christ as our Immanuel is that it is by His accomplished and continuing work that the accusations and opposition of Satan are nullified; made of no effect. Manifest though the schemes and suggestions of Satan and his minions may be, great though his power and influence may be (or have been), it is incomparable to the God of the Universe who is with us and for us.
If we imagined Satan as the prosecution's key witness (as when God, the judge of all the heavens and earth, says, "consider my servant Job" to Satan) we could also imagine God the son as the key witness in our defense (as when Job's self-defense seems hopeless and he cries, "I know that my Redeemer lives, and at the last he will stand upon the earth," Job 19:25). The Lord God of Truth, the Logos of God, the Wisdom and Power of God stands between the judge and the accused and pleads His own righteousness in their stead: for He is God with us, Immanuel. Therefore James can say, "But he gives more grace. Therefore it says, “God opposes the proud, but gives grace to the humble.” Submit yourselves therefore to God. Resist the devil, and he will flee from you" (James 4:6-7). With the judge appeased and satisfied in his justice He no longer stands in judgment, but has declared righteousness for our account and can no longer take account of Satan's accusations. His testimony is out of order. His claims have no claim upon those in Immanuel's hands.
Therefore the believer must, as James says, submit himself to the judge, who is now no longer judge, but Father, by virtue of the sonship conferred upon those claimed by the Son, as joint heirs. The voice of God no longer condemns, but disciplines. He no longer stores up wrath, but pours out mercy. He no longer sits upon the bench to execute vengeance on us, but draws us up onto his knee to train us in His grace. Where before we feared God and despaired of His wrath, now we fear God and marvel of His love, for,
"By this we know that we abide in him and he in us, because he has given us of his Spirit. And we have seen and testify that the Father has sent his Son to be the Savior of the world. Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. So we have come to know and to believe the love that God has for us. God is love, and whoever abides in love abides in God, and God abides in him. By this is love perfected with us, so that we may have confidence for the day of judgment, because as he is so also are we in this world. There is no fear in love, but perfect love casts out fear. For fear has to do with punishment, and whoever fears has not been perfected in love." (1 John 4:13-18 ESV)
And if God loves us, Satan's hate is of no effect. Neither can sin have any power over us that we cannot defeat,
"For this is the love of God, that we keep his commandments. And his commandments are not burdensome. For everyone who has been born of God overcomes the world. And this is the victory that has overcome the world—our faith. Who is it that overcomes the world except the one who believes that Jesus is the Son of God?" (1 John 5:3-5 ESV)
The believer in Christ need not bear any accusation, however many reproaches he must endure, for the love of God is for him, to grow him up into perfection through however many trials and falls and redirections may be required. Let no son of God fear the reproach of God or of a brother or of an unbeliever, for they are all the gentle hand of the Father to bring him up into the image of the Son by the power of the Holy Spirit.