Job had complained that God would not give him a fair hearing, even if he were innocent (Job 9:2, Job 9:12). Zophar responds with his strong belief in the doctrine of retribution. It is true that Job will not stand a chance if God convenes a court against him. But this is because Job is guilty, not because God is unjust.
10 If he passes through and imprisons and summons the court, who can turn him back?