At the opposite, we do have knowledge of their 'aqidah, and it's on this very basis that the Ulama have made takfir of them. We're not talking about actions and sins here, that we can have husn ad-dann; we're talking about 'Aqa'id... Same could be said for Qadyanis, jews and christians.. Open doors for them, too? And in fact it was Shi'ah separating themselves from Islam. Fitna is worse than murder, indeed.