On the contrary. I would say that if God took the time to give you grace and faith wouldn't He give you ENOUGH grace and faith to keep you going? I would suggest that anything outside of this reasoning is inconsistent unless one wants to say that it is man's works that saves him. Then you get into another sticky issue.
As far as the heretics in the early church, Johns plainly recognized this fact and states that they were NEVER part of us because if they had been of us they would have continued with us. The reason God gives us heretics is so that we can see what is false gospel. Our Lord Jesus has always stated there would be the wheat and the tares. (1 John 2:19) It is my personal belief that we all hold errors and God's divine reasoning for mixing genuine Christians up with tares is so that we CAN sort out the truth if we are honest with ourselves.
Those who are of the true Christian faith will continue with Christ simply because of God's grace and mercy in His bestowing upon His chosen His faith. Would you disagree with this last sentence?
Those who are of the true Christian faith will continue with Christ simply because of God's grace and mercy in His bestowing upon His chosen His faith.
The sticking point is the understanding of the word chosen. While I can't speak for everyone who believes in free will, I think most in that camp would say that God chooses everyone for communion with Himself, that is the experience of grace, theosis, salvation, sanctification. But this is an encounter that involves reciprocity--a relationship of person to Person. Personhood requires freedom of response. And that also entails the freedom to fail and miss the mark.