Overcometh what? He that overcomes the temptations of the materialistic world. She that overcomes the desires of the ego. But there are many who don't have an ear, meaning a spiritual ear necessary to hear and understand things of a spiritual nature, and they don't understand. And what is “the second death”? The spiritual death, with the death of the physical body being the first. But isn't the spirit and soul immortal? Yes, but you will nonetheless die spiritually if you don't awaken and nurture that spirit and soul. If you don't, then when your body dies, the spirit and soul will go to heaven, but without you.