Is it possible to want so much to believe that you can be deceived into believing that Christ died for you? I have been struggling with this issue. The Bible strongly warns that there is an adversary prowling around like a roaring lion, seeking whom he can devour. Can he deceive you to think that you believe in your heart when you only have mental knowledge, no matter how hard you pray?
No. This cannot happen. If Satan had the power to trick someone who sincerely comes to the Lord in faith and asks to be saved, then who could be sure of their salvation? Besides, the Bible says every one who asks receives (Matt. 7:7-8), and if you confess with your mouth Jesus is Lord and believe in your heart God raised Him from the dead you’ll be saved (Romans 10:9), and everyone who calls upon the name of the Lord will be saved (Romans 10:13). These are promises from God and when He makes a promise He keeps it. Not even Satan can spoil a promise from God.
Jesus said, “I tell you the truth, no one can see the Kingdom of God unless he is born again” (John 3:3). The way Satan tricks people into thinking they’re saved when they’re not is by convincing them there’s a way to be saved that doesn’t involve being born again. For example, some groups teach that people can be saved by joining their church. Others say people can be saved by following their rules. Still others say salvation comes through the acquisition of secret knowledge. The list goes on.
But Jesus said, “I am the way, the truth, the life. No one comes to the Father but through me” (John 14:6). If you have come to the Father because you believe Jesus died for your sins and rose again, you have come the right way, the only way.