Look at the difference between an upright and a crooked heart. The righteous man realizes that when afflictions or sorrow or humiliations fall on him it is by God's holy will, and so accepts it. The man with a twisted and perverted heart puts up with it angrily. He agrees that he is a sinner, but says there are many worse than he who are happy.
In fact there are three arguments that his crooked heart puts forward: either there is no God - the fool says that - or God is unjust, or God does not rule the lives of men, and disinterests himself in what happens to them. The upright heart accepts whatever happens to him, saying 'The Lord has given, the Lord has taken away; as it pleased him so he has done: blessed be the name of the Lord'.
Your tribulations come from God - a punishment for the sinner, a chastisement for the son. If you wish to be a son, don't expect to escape pains, for 'He chastises every son he receives'. Every son? Without exception?
Listen. The only begotten Son was without sin, and yet he suffered. He took to himself our infirmity, the head bearing the members of the body in his person. As man he went to his Passion sorrowful that you might rejoice, in anguish that you might be consoled. He said, 'My soul is sorrowful even unto death, but not what I will but what you will, Father'.
DAILY READING WITH
St Augustine --- The Heart at Rest