What is the ruling on participating in a non-Sunni forum?

The ruling on participating in these forums varies depending on the individuals: It is not permissible for the general public to participate for fear of being influenced by falsehood or denying the truth. However, for someone who possesses religious knowledge and insight into matters of creed, and wishes to engage in dialogue with people of deviation kindly in order to guide them, then this is an obligation upon him and a great good, for the Prophet, peace and blessings be upon him, said: "By Allah, that Allah guides a single man through you is better for you than red camels," and "Indeed, the one who points to good is like the one who does it."