Original: Marcionism is an Early Christian dualist belief system that originated in the teachings of Marcion of Sinope at Rome around the year 144 ; ( 115 years and 6 months from the Crucifixion , according to Tertullian 's reckoning in Adversus Marcionem , xv ) see also Christianity in the 2nd century .
Simplified: Marcionism is an type of Christianity which started around 144 ( According to Tertullian in Adversus Marcionnem , it started 115 years and 6 months after the Crucifixion of Jesus ) .