Clearly, Christ being in us, we must yield to the Holy Spirit, if God is going to work through us.
That is where our will comes into effect, to sin or not sin, to do God's will or not.
All that may seem accurate in our day-to-day perceptions, but if God intends for our salvation by Christ's definitive redemption, how can anything truly thwart it?
I just cannot believe the names in heaven depend on men's good choices, or that even one drop of the shed blood of Christ can come to naught.