The relationship between historia salutis and ordo salutis is crucial to our salvation. God's plan for our redemption is not just redemptive in character and purpose (i.e., to be delivered from hell and spared from our punishment); it is also transformative (i.e., to be changed from a sinner to a saint). In fact, it is truly redemptive because it is transformative. What is ordo salutis in essence? It is the process by which a hell-deserving sinner is made into a God-loving, law-delighting saint, glorified and perfected in the image of God.
Think about how crucial this redemptive transformation is in salvation. What does it profit a sinner to make it to heaven if his wicked heart is not changed? As someone said, if that were to happen, there would be two hells--the hell reserved for Satan and unrepentant sinners and the heaven in which the sinner finds himself. How intolerable would heaven be for the sinner who hates God to have to obey and delight in Him! No, heaven will not be heaven unless we are made good, holy, and righteous in our whole being, loving the Lord of heaven with all of our heart! And this is what ordo salutis is about.