According to the christian worldview, a person is justified in feeling angry with god in the midst of suffering because, according to the sufferer: they do not deserve to suffer.

Since your question doesn't really pose for a direct answer, I think this is a true or false statement. For me, I think this is false.

Especially for Christians, this thought is definitely not true. Christians believe that God and Jesus Christ provides for everything. In the New Testament, Jesus Christ has suffered a great deal to shoulder all our sins in order to save us. So, it is the faith of the Christians that they owe everything to the Lord. In return for saving them, Christians would have to follow Jesus' footsteps and have their own battles to face. Hence, a Christian being angry to God is normal, but unjustifiable.

What document are you referring to