Who shall bring a charge against God’s elect? It is God who justifies. Who is he who condemns? It is Christ who died, and furthermore is also risen, who is even at the right hand of God, who also makes intercession for us. – Romans 8:33-34
No weapon that is formed against you shall prosper; and every tongue that shall rise against you in judgment you shall condemn. This is the heritage of the servants of the LORD, and their righteousness is of me, said the LORD. - Isaiah 54:17
And I heard a loud voice in heaven, saying, “Now the salvation and the power and the kingdom of our God and the authority of his Christ have come, for the accuser of our brothers has been thrown down, who accuses them day and night before our God. 11And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death. 12Therefore, rejoice, O heavens and you who dwell in them! But woe to you, O earth and sea, for the devil has come down to you in great wrath, because he knows that his time is short!” - Revelation 12:10-12
By the blood of the Lamb we overcome Satan as the accuser of the brethren. The chapter (Revelation 12) expressly tells us that he accuses the brethren day and night; and there is an instructive tradition among the Jews that Satan accuses the elect of God all day and all night long, except on the day of atonement, and then he is quiet. Glory be to the dying Lamb, the atonement shuts the mouth of the lion continually, for the atonement lasts all the year round. Neither in the court of Heaven, nor in the court of conscience, can the enemy’s accusations harm us, for the blood of our Substitute is a bar to all suits against us.
If we by faith are assured that Jesus has put away our sin, what cause have we for alarm? If the punishment due to our sin, and the sin itself have both been carried away by our great Surety, so that sin is plunged into the depths of the sea, and cast behind God’s back, then who is he that shall harm us? Brethren, do but grasp the doctrine of the atonement, and know your own interest in it, and the accuser of the brethren will be silenced by the voice of the blood.
We overcome Satan by the same means as to his craft. He has seven heads, but we tell him Jesus died, and that breaks all the seven heads, and destroys the sevenfold ingenuity of his snares. He would, if it were possible, deceive even the very elect, but the secret of the sprinkled blood is that which prevents the elect from ever being deluded by him. Who shall separate them from the love of Christ? Does not redemption by blood hold them fast to their Redeemer? You cannot be right anywhere if you are wrong upon the atonement, but if you are sound upon the substitutionary sacrifice there is little fear of your falling into any serious error.
As the needle once magnetized continues to seek the pole, so they who are once touched with the love of their dying Surety are sure to remember it and cannot long be turned in any other direction. As for the dragon’s horns of power; the power of the blood is far greater. Since we have been redeemed by Christ from under the power of Satan he cannot regain his hold of us. His power is broken. As to the crowns which he wears, what care we for them? We are delivered from under his power by being redeemed by the blood of Jesus Christ, and Satan can never again have the rule over us.
As for the energetic influence which is figured by his tail, he may quench the very stars of heaven, and pull down the most brilliant professors and make them fall to the earth as apostates, but he cannot harm us, for because of the blood of Jesus we are latest by the power of God through faith unto salvation. Cling to the cross, dear brethren, for there you are out of the reach of the old serpent’s venom; he may hiss, but he can do no more. No wave can ever wash a poor sinner off from the rock of ages, no storm can drive a penitent out of the clefts of the rock. Within the wounds of Jesus we are secure from all the rage of Satan. In our battles with Satan we need no other artillery but the atoning blood, it meets and conquers him at all points.
–Charles H. Spurgeon