Let it be said: Christianity cannot simply be anything claimed by anyone who calls him or herself Christian. Christians must follow the teachings, examples, spirit, and word of Jesus. Christianity can only originate with Christ and within the hearts and actions of people inspired by Christ, staying true to the integrity of the Gospels.
"Christianism" is what happens when one veers from the integrity of the Gospels and misuses (intentionally or unintentionally) the message of Christ to forward very unChristian aims. Jesus brought with a message of forgiveness, love, hope, gentleness, compassion, and inclusion. "Christinism", on the other hand, twists that message into its opposite: intolerance, self-righteous moralism, homophobism, sexism, racism, and increasingly classism.