Every religion is poison for the brain. Believers believe the words of religious leaders and are not able to analyze the words and actions. If the Patriarch goes to the Mercedes S class then how can you believe him about what the pursuit of luxury is a sin?
Said one such politician called Ilich Lenin that religion is opium for the people. This he saw because he was afraid that the church controls people and not him. But it is not possible to poison Christianity. Therefore, how can you call Christianity a poison.