How can grace be irresistible if at times Jesus called and some rejected?

Question:  I have heard irresistible grace to be:  at the moment of your salvation, it was impossible to turn away from His grace.   Is this understanding correct?  It seems like there were times in the NT when Jesus called and some rejected…how then was God’s call irresistible?

First of all, I think irresistible is a poor term to describe God’s grace in the salvation experience (and the word’s hard to type too!  Try it!).  I think overcoming is a much better word because it shows how God goes to great lengths to overcome our objections to him.  Having said that, one only need to listen to Jesus’ lament in Matthew 23:37, “O Jerusalem, Jerusalem, you who kill the prophets and stone those sent to you, how often I have longed to gather your children together, as a hen gathers her chicks under her wings, but you were not willing.”  Here, it is clear that Israel rejected God’s messengers–His prophets.

Second, this question requires us to delve into God’s general call and his effectual call.  Check out the first question in this series: “Does God woo all?”