[Popman]

Christians and muslims actually worship the same God?

Depends: "I testify that there is no God but Allah," and the other "I testify that there is no deity but God."

[stuartcr]

If a person, regardless of their faith or the name they use for God, prays for God’s help, who would hear them?

Could false god even exist, outside of someone’s mind?

Who created those people that believe in a false god?