I think that regret and remorse are extremely important to Edwards' sermon. The primary motivation of the sermon is for individuals to recognize how intensely angry and disappointed Edwards' conception of God is with humanity. Edwards is animated by the idea that God is going to take action against those who sin. The idea of "in due time" is something that indicates that unless individuals repent and sincerely feel bad for what they have done, they will not be able to receive God's mercy and his compassion. It is here where Edwards makes it clear that individual remorse followed by sincere repentance are the only key elements to ensure that God's divine mercy is evident. If not, the results will be to incur God's wrath. The conception of God is one whereby anger and intensity are so present that the only feasible option to placate this vision of the divine is through the idea of ensuring that remorse is part of the individual's path to salvation. Absence of this remorse simply means that individuals continue to run the risk of an "angry God," something that Edwards distills in distinct and clear terms.