Christ as our sole Mediator, Atoning Sacrifice, High Priest, and Intercessor...

Our churches teach that the history of saints may be set before us so that we may follow the example for their faith and good words, according to our calling.  For example, the emperor may follow the example of David in making war to drive away the Turk from his country.  For both are kings.  But the Scriptures do not teach that we are to call on the saints to to ask the saints for help.  Scripture sets before us the one Christ as the Mediator, Atoning Sacrifice, High Priest, and Intercessor.  He is to be prayed to. He has promised that He will hear our prayer.  This is the worship that He approves above all other worship, that He be called upon in all afflictions.  "If anyone does sin, we have an advocate with the Father" (I John 2:1).
~BOC, AC, XXI, 1-4

Even the Prophets and the Psalms teach free mercy and forgiveness of sins by faith...

Throughout the Prophets and the Psalms this worship (this latreia) is highly praised, even though the Law does not teach the free forgiveness of sins.  The Old Testament Fathers knew the promise about Christ, that God for Christ's sake wanted to forgive sins.  They understood that Christ would be the price for our sins.  They knew that our works are not a price for so great a matter.  So they received free mercy and forgiveness of sins by faith, just as the saints in the New Testament.  To this point belong those frequent repetitions about free mercy and forgiveness of sins by faith that appear in the Psalms and the Prophets.  For example, Psalm 130:3 says, "If You, O LORD, should mark iniquities, O Lord, who could stand?"  Here David confesses his sins and does not list his merits.  He adds, "But with You there is forgiveness" (v.4). Here he comforts himself by his trust in God's mercy, and he refers to the promise, "I wait for the LORD, my soul waits, and in His word I hope" (v. 5).  This means, "Because You have promised the forgiveness of sins, I am sustained by Your promise."  Therefore, the Fathers also were justified, not by the Law, but by the promise and faith.  It is amazing that the adversaries diminish faith to such a degree, even though they see that it is everywhere praised as a great service.  For example, Psalm 50:15 says, "Call upon Me in the day of troubles; I will deliver you."  God wants Himself to be known.  He wants Himself to be worshipped, so that we receive benefits from Him and receive them because of His mercy, not because of our merits.  This is the richest consolation in all afflictions.  The adversaries band such consolation when they diminish and disparage faith and teach only that by means of works and merits people interact with God.
~BOC, AP, IV (II), 57-60

That the works of God might be displayed in us...

Job is excused though he was not troubled by past evil deeds.  Therefore, troubles are not always punishments or signs of wrath.  Indeed, terrified consciences should be taught that there are more important purposed for afflictions, so that they do not think God is rejecting them when they see nothing but God's punishment and anger in troubles.  The other more important purposes are to be considered, that is, that God is doing His strange work so that He may be able to do His own work, as Isaiah 28 teaches in a long speech.  When the disciples asked about the blind man who sinned, Christ replies that the cause of his blindness is not sin, but that "the works of God might be displayed in him" (John 9:2-3).  In Jeremiah it is said, "If those who did not deserve to drink the cup must drink it..." (49:12).  So the prophets, John the Baptist, and other saints were killed.  Therefore, troubles are not always punishments for certain past deeds, but they are God's works, intended for our benefit, and that God's power might be made more apparent in our weakness.
~BOC, AP, XII (VI), 61-63