"'When your children sinned against him, he gave them over to the penalty of their sin.'" NIV translation
Can you imagine telling a grieving person that the reason their child has died was because of their sin? That is basically what Bildad has done and we remember that Job had been concerned about his children sinning as he had constantly offered sacrifices just in case they had sinned. Bildad's logic was based on a partial truth as, under the Law of Moses, the penalty for sin is death but the law did not say that every death was due to the sins of the departed person.
Because he did not understand the nature of God and have insight into spiritual matters, Bildad just assumed that, since they were dead, they had to have been punished for their sin.
It is sad to say but the same type of thing happens today even among Christians. Many Christian people have been passed on this same tradition without spiritual insight and so, when they see bad things happening to someone, they automatically assume that there is a hidden sin.
"'But if you will seek God earnestly and plead with the Almighty, if you are pure and upright, even now he will rouse himself on your behalf and restore you to your prosperous state.'" NIV translation
Now, Bildad continues to heap insults on Job by basically calling him a hypocrite as he tells him to seek God "earnestly". He implied that Job had been pretending to be a man of God while all the time he was hiding his sin. Once again we see that Bildad was just relying on the teaching of his ancestors as he says that God will restore his wealth if he is "pure and upright". Although Job will be returned to prosperity by God, it will not be because he has done anything but trust in God.
This brings to mind the questions of: Are there hypocrites in the church and what does that mean? The answer to the first part of the question is a definite yes. A hypocrite is basically an actor and, in relation to the church, this could speak of two types of people. The first is someone that is going through the religious motions of showing up to the church but not really accepting Jesus Christ as their Savior. The second is a person that shows up at the church and pretends to be a "super saint" and without sin in their life while at home their lives are a mess. How do you answer the charge of being called a hypocrite? First, if you claim to be a Christian, make sure you have accepted Jesus Christ as your personal Savior and don't put your hope in the family tradition of attending "church". Second, acknowledge the fact that you sin on a daily basis (we all do so) but remind your accusers that your sin was paid for by Jesus Christ.