You are assuming the grace God given in that moment is for the sole purpose of saving in that moment.
There is a whole process of people receiving God's grace that leads to salvation before salvation is effected. There are those who reject that grace along the way and therefore are never given the grace of the Gospel which is the power of God unto salvation. The Romans 1 type springs to mind.
You keep making assumptions based on your own understanding. Stop putting my words in your world paradigm. One of the beautiful things about being created in God's image is our ability to be semi-transcendent. We can step out of our own shoes to some degree and put ourselves in the shoes of another. If we want to truly understand others, we have to do that sometimes.