Indeed,, Heretic is what one sheep pen calls a member of another sheep pen.. (John ch 10) We are instructed to even love our enemies... Which might include members of Goat pens too.. i.e. Buddist, Hindu, Muslim, Mormon, Jewish, JW's,, other so-called non christian pens..
People seeking "GOD" start at all kinds of "observation" points.. and do the best they can do with what they have to work with.. The Holy Spirit has one heck of a job, no doubt.. Which makes "our" tesimony even more important.. as a model or example.. A hateful testimony can't be a good thing..
To God be the glory!