I am not the gatekeeper to heaven, and neither are you.  And we shouldn't boil the Gospel down into multiple doctrines demanding a thorough affirmation of every primary doctrine that we consider essential for salvation.   I however, believe, a more prudent approach to people would be that we should only lack confidence in someone's conversion if they consistently reject a fundamental tenet.  It might be wiser to concentrate on whether we would admit such an individual into voting rights or teaching recognition in the church rather than speculate about the condition of their soul.   It's God's prerogative to oversee access to heaven, while it's ours to oversee membership in the congregation.