Some religions make no mention of Satan as a reality. Others include him as a reality and enemy, yet they make little or no accounting of him actively working to destroy mankind and God's purpose. Jesus makes no bones about Satan actively working to destroy men. In John 8:44, in accusing the Jews of unbelief, He puts Satan's nature in plain words:
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.
Satan is clearly responsible for drawing Adam and Eve into the first of mankind's sins, opening the floodgate to the sins of all of their progeny, all physical and mental sickness, countless emotional agonies, and the billions of deaths that mankind has experienced.
God makes it clear that the wages—the ultimate penalty—earned by one's sins is death (Romans 6:23). The sobering truth of this matter is that it takes only one sin for God to impose the death penalty! He warned Adam and Eve in the Garden of Eden before they ever sinned, "In the day you eat of it you shall surely die" (Genesis 2:17). The death penalty falls immediately on anyone who sins, even if it is the first time!
Any religion that is without Christ leaves the door open to thoughts that salvation can be earned by means of good works. The idea is that the evil an individual has done in the past can be compensated for by doing good deeds. This is the very charge the apostle Paul lays against the Jews in Romans 10:1-4:
Brethren, my heart's desire and prayer to God for Israel is that they may be saved. For I bear them witness that they have a zeal for God, but not according to knowledge. For they being ignorant of God's righteousness, and seeking to establish their own righteousness, have not submitted to the righteousness of God. For Christ is the end of the law for righteousness to everyone who believes.
In order for one to be justified before God and accepted by Him requires a righteousness that no man who ever sinned even one time can achieve. No amount of good works can compensate for even one sin. God will accept only the righteousness of One who has never sinned, and He will accept that payment only when a repentant sinner by faith believes.
Peter's statement in Acts 4:12 confirms that salvation is found nowhere else: "There is no other name under heaven given among men by which we must be saved" (emphasis ours). Christ's involvement in the forgiveness of sin for salvation is imperative; there is no alternative! Peter is not saying we can be saved or may be saved. The word "must" reveals necessity according to God's decree. Salvation is found through no other person and no other way of life except through the sacrifice of Jesus of Nazareth.
Salvation denotes deliverance or preservation from harm or evil. In this case, it is deliverance and restoration from the effects of sin. The result, then, is deliverance from eternal death (unless one goes on from that point to commit blasphemy of the Holy Spirit, which Jesus says God will not forgive; see Matthew 12:31-32). This is because salvation begins upon one's repentance from his sins and faith in the sacrifice of Christ for the forgiveness of sins. This combination of acts justifies a person before God, and no human works, regardless of their quality or quantity, are acceptable for the forgiveness of sins.
Does any other religion have a Savior with the qualifications of Jesus Christ? No other religion offers such a magnanimous gift. Forgiveness, and therefore justification, is available only through that perfect sacrifice, along with the sincere repentance of a believing sinner who exhibits faith in the God/Man Jesus Christ and in God's grace. God will then give us of His Spirit.