Worship only God

The Bible demands that we worship God, and only God. The first and second commandments are:

• You shall have no other gods before me.
• You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them; for I, the LORD your God, am a jealous God, punishing the children for the sin of the fathers to the third and fourth generation of those who hate me, but showing love to a thousand {generations} of those who love me and keep my commandments.
  

Worshiping other gods is punishable by death. The kings who killed prophets of other gods are lauded for their zeal for the Lord. God punished by death those who failed to consult him or properly respect him.

Say it is true; God is the only one worthy of our worship and those who worship other gods are foolish. Does that mean it is right for God to demand our worship on pain of death? If someone foolishly worships a fake god, is that threatening to God? Why can't he just laugh at that man's foolishness? If someone wants to choose a different god, why not just let him? My only explanation for this defensiveness on God's part is that he feels threatened by people following other gods. But it is kind of surprising that an infinite God would feel threatened by mere mortals. That is the kind of behavior Imight expect from an autocrat fearful of possible usurpers.

I'm not sure what to conclude. If indeed God is not satisfied unless everyone worships him and he punishes those who don't, then the Christian God must be insecure and vindictive. How can I honestly worship someone like that?