Standing one day and falling the next is the nature of our life...

Although we have received forgiveness and a good conscience and are entirely acquitted, yet our life is of such a nature that we stand today, and tomorrow we fall.  Therefore, even though we are godly now and stand before God with a good conscience, we must pray again that He would not allow us to fall again and yield to trials and temptations.
~BOC, LC, III, 100

The consolation in God's power made apparent in our weakness...

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 purposes 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 replied 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), 61-62