see Christianity doesn't teach that at all. We don't disappear when we turn to God in Christ, we are reborn (as Jesus told Nicodemus one must be born again). When you trust in Christ, you are crucified with him, your old man is put to death and you are raised up a new man (that's why we baptize, symbolizes our death and resurrection just as Christ was dead, buried, and rose up). There is a real spiritual transformation that takes place, one that is made evident in the way a person lives from that point forward. As Paul puts it, we have risen "to walk in newness of life." eveyrthing about the christian life after conversion is new.
Ezek 36, says I?ve received new heart, Ezek 18, says I?ve received a new spirit, Gal 6, says I am a new creature, Eph 4, says I am a new man, Rev. 2, says I have a new name, psalm 40, says I have a new song, 2 Corinthians 5:17 says that ?If anyone is in Christ he is a new creation, the old has gone, the new has come.?
Ezek 36, says I?ve received new heart, Ezek 18, says I?ve received a new spirit, Gal 6, says I am a new creature, Eph 4, says I am a new man, Rev. 2, says I have a new name, psalm 40, says I have a new song, 2 Corinthians 5:17 says that ?If anyone is in Christ he is a new creation, the old has gone, the new has come.?