This is an excerpt of a sermon written by Edwards titled " How to Know if You Are a Real Christian". To read the whole sermon, click here
"We may make several conclusions based on these truths. First, that no matter how much people may know about God and the Bible, it is no sure sign of salvation. The devil before his fall, was one of the bright and morning stars, a flame of fire, one excelling in strength and wisdom. (Isa. 14:12, Ezek. 28:12-19) Apparently, as one of the chief angels, Satan knew much about God. Now that he is fallen, his sin has not destroyed his memories from before. Sin does destroy the spiritual nature, but not the natural abilities, such as memory. That the fallen angels do have many natural abilities may be seen from many Bible verses, for example Eph 6:12 "For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms." In the same way, the Bible says that Satan is "more crafty" than other created beings. (Gen 3:1, also 2 Cor. 11:3, Acts 13:10) Therefore we can see that the Devil has always had great mental ability and is able to know much about God, the visible and invisible world, and many other things. Since his job in the beginning was to be a chief angel before God, it is only natural that understanding these things has always been of first importance to him, and that all his activities have to do with these areas of thoughts, feelings, and knowledge.
Because it was his original employment to be one of the angels before the very face of God, and sin does not destroy the memory, it is clear that Satan knows more about God than just about any other created being. After the fall, we can see from his activities as a tempter, etc., (Matt 4:3) that he has been spending his time increasing his knowledge and its practical applications. That his knowledge is great can be seen in how tricky he is when tempting people. The craftiness of his lies shows how clever he is. Surely he could not manage his deceit so well without an actual and true knowledge of the facts.
This knowledge of God and his works is from the very beginning. Satan was there from the Creation, as Job 38:47 shows: "Where were you when I laid the earth's foundation? Tell me, if you understand. . .while the morning stars sang together and all the angels shouted for joy?" So he must know much about the way God created the world, and how He governs all the events in the universe. Furthermore, Satan has seen how God has worked his plan of redemption in the world; and not as an innocent bystander, but as an active enemy of God's grace. He saw God work in the lives of Adam and Eve, in Noah, Abraham, and David. He must have taken a special interest in the life of Jesus Christ, the Saviour of men, the Word of God incarnate. How closely did he watch Christ? How carefully did he observe his miracles and listen to His words? This is because Satan has set himself against Christ's work, and it is to his torment and anguish that Satan has watched Christ's work unfold successfully.
Satan, then, knows much about God and God's work. He knows heaven first-hand. He knows hell also, with personal knowledge as its first resident, and has experienced its torments for all these thousands of years. He must have a great knowledge of the Bible: at the least, we can see he knew enough to try tempting our Saviour. Furthermore, he has had years of studying of the hearts of men, his battlefield where he fights against our Redeemer. What labours, exertions, and cares the Devil has used over the centuries as he has deceived men. Only a being with his knowledge and experience of God's working, and the human heart, could so imitate true religion and transform himself into an angel of light. (2 Cor 11:14)
Therefore we can see that there is no amount of knowledge of God and religion that could prove a person has been saved from their sin. A man may talk about the Bible, God, and the Trinity. He may be able to preach a sermon about Jesus Christ and everything He has done. Imagine, somebody might be able to speak about the way of salvation and the work of the Holy Spirit in the hearts of sinners, perhaps even enough to show others how to become Christians. All these things might build up the church and enlighten the world, yet it is not a sure proof of the saving grace of God in a person's heart.
This is an excerpt of a sermon written by Edwards called "How To Know if You Are a Real Christian". To read the whole article click here
It also may be seen that for people to merely agree with the Bible is no sure sign of salvation. James 2:19 shows that the demons really, truly, believe the truth. Just as they believe there is one God, they agree with all the truth of the Bible. The devil is not a heretic: all the articles of his faith are firmly established in the truth.
It must be understood, that when the Bible talks about believing that Jesus is the Son of God, as a proof of God's grace in the heart, the Bible means not a mere agreement with the truth, but another kind of believing. "Everyone who believes that Jesus is the Christ is born of God." (1 John 5:1) This other kind of believing is called "the faith of God's elect and the knowledge of the truth that leads to godliness." (Titus 1:1) There is a spiritual holding to the truth, which will be explained later on."