It is a profound gift of grace that God has not only promised us forgiveness, but that he has established the foundations of it right before our eyes.
The death of Jesus Christ is an eternal testimony before God that our sins have been sufficiently dealt with, which gives us confidence that we will receive mercy on the Day of Judgment and not wrath.
Jonathan Edwards ponders the alternative in Miscellanies #113:
Again, if there was no satisfaction for sin, nor any promises of forgiveness; seeing the best are daily renewing their sins, they would [be] in a dreadful case, not knowing whether there be any hope for pardon again, seeing God had pardoned them so often after they had renewed their disobedience.
But the reality is that Jesus "entered once for all into the holy places . . . by means of his own blood, thus securing an eternal redemption" (Hebrews 9:12). Let us praise him.