It is possible that anyone could be Jesus Christ returned. We don't know what sort of sign God would give us if his Jesus were reborn into the world. So, it's a definite possibility since there's no way to prove that he isn't.
The founder of Christianity is Jesus Christ.
Jesus CHRIST! (hence the Christ....)
Jesus Christ.
Jesus Christ
jesus christ
jesus christ
It was Jesus Christ.
The Lord Jesus Christ.
Christ aka God the Son
Jesus Christ is the founder of christianity.
Basically, Jesus Christ.
The founder was Jesus of Nazareth, whom Christians know as Jesus Christ, or Jesus the Christ.