Curse you to your face

[tonychanyt]

Job routinely prayed for his children. Job 1:

5b He would rise early in the morning and offer burnt offerings according to the number of them all. For Job said, “It may be that my children have sinned, and cursed [H1288] God in their hearts.” Thus Job did continually.

Speaking or thinking about God negatively was a sin but it was forgivable by burnt offerings.

Satan accused Job:

9 Satan answered the Lord and said, “Does Job fear God for no reason? 10 Have you not put a hedge around him and his house and all that he has, on every side? You have blessed the work of his hands, and his possessions have increased in the land. 11 But stretch out your hand and touch all that he has, and he will curse you to your face.”

This cursing was more serious: Curse God to God's face directly and defiantly. This was more like blasphemy by denouncing God publicly.

Did it mean to call God a bad word or did it mean Job would say he no longer wants to serve God?

It was more toward the latter. Job 1:5 illustrates a concern for internal faithfulness and righteousness, while Job 1:11 highlights an external challenge to loyalty and integrity in the face of adversity.