Anyone who belongs to Christ is a new person!
The Jewish and Christian God are the same. Islam has a man-made god which is false. Jewish and Islam believers, if they were to die today, would not go to heaven.
How do the Jews and Christians have the same God? Good question, the Christians believe God came to earth as a man named Jesus Christ. We believe Jesus was the perfect sacrifice without sin. Jesus shed His blood for us. Without blood there is no forgiveness of sins. The Jewish belief has animal sacrifices to cover their sins and do not acknowledge Jesus as the Savior. Once Jesus died on the cross for us, He did not allow blood from animal sacrifices to cover sins anymore.
As for Islamists, they believe Jesus was a prophet and not God. They believe that good works has to outweigh the bad works, which is a works based religion. Christians believe salvation is a gift of God. (Once we are saved though, we will have evidence of it with good works, but our works do not save us.)
If you are not following Jesus you are following a thief. Jesus said, “The thief comes only to steal and kill and destroy; I have come that they may have life, and have it to the full.” (John 10:10)
The devil is this thief that comes up with false teachers and religions. False teachers and religions only come to steal, kill, and destroy. So this makes the devil a liar. We have already learned that Jesus is the truth. Do you want to follow a liar or the way, the truth, and the life?