How do we respond to someone who asks why we do NOT pray for Satan's salvation?
While the potential for change is exists, one thing that many people have a hard time accepting is the fact that some people won't ever change; not because they are unable to change, but because they are unwilling to change.
We should intercede on behalf of those who sin, especially on behalf of those who ask us (James 5:15). But there are times when God says not to pray for certain sinners.
When Israel fell so deeply into idolatry that the Lord decided to send the entire nation off into captivity, God told Jeremiah, "Therefore do not pray for this people, nor lift up a cry or prayer for them, nor make intercession to Me; for I will not hear you" (Jeremiah 7:16). And again, "So do not pray for this people, or lift up a cry or prayer for them; for I will not hear them in the time that they cry out to Me because of their trouble" (Jeremiah 11:14). Why? Because it was too late. The decision had been made, the punishment decided. To pray at this point would be to pray against the will of God. It would be a cry that God's justice was wrong and that the people should not be punished. The only path for this people was death or captivity. "Then the LORD said to me, "Even if Moses and Samuel stood before Me, My mind would not be favorable toward this people. Cast them out of My sight, and let them go forth. And it shall be, if they say to you, 'Where should we go?' then you shall tell them, 'Thus says the LORD: "Such as are for death, to death; and such as are for the sword, to the sword; and such as are for the famine, to the famine; and such as are for the captivity, to the captivity."" (Jeremiah 15:1-2).
In the New Testament, John says much the same, "If anyone sees his brother sinning a sin which does not lead to death, he will ask, and He will give him life for those who commit sin not leading to death. There is sin leading to death. I do not say that he should pray about that. All unrighteousness is sin, and there is sin not leading to death" (I John 5:16-17). Sins leading unto death are those which are unrepented. When people turn from sin, we should pray on their behalf for forgiveness. We might even pray that a person be made aware of their sins and that their hearts be soften so that they will repent. But when a person refuses to see their sin and remain unrepentant, then to pray that they be saved while they remain opposed to God is to deny justice.
Jesus told us, "You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it" (John 8:44). Satan has no interest in salvation. He has declared his opposition to God and continues to work against Him. God has already placed him and his followers under condemnation. "For if God did not spare the angels who sinned, but cast them down to hell and delivered them into chains of darkness, to be reserved for judgment" (II Peter 2:4). His destruction is foretold, "The devil, who deceived them, was cast into the lake of fire and brimstone where the beast and the false prophet are. And they will be tormented day and night forever and ever" (Revelation 20:10). Jesus said it would happen. "Then He will also say to those on the left hand, 'Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels'" (Matthew 25:41).
God, in His great wisdom and unbounded mercy, has stated that Satan and his followers will not be saved. Eternal punishment has already been prepared. All that stands in the way is God's decision to bring this world to an end and to give final judgment to all. To pray for Satan's salvation is to say that God was wrong in His condemnation of Satan. Knowing that Satan will never change, to pray for his salvation is to pray that God change His will and accept people who will not accept Him. In an indirect way, it is giving approval to Satan and what he represents. Such would not be right.