Just as most people go to school because they are promised good jobs afterwards,
Terrorist blow themselves up because they are promised 42 virgins in Paradise.

is it safe to say religion wouldn't exist if these promises were never made?

.

For those who have truly been mercifully pardoned and drawn to the Lord Jesus Christ/God... it is primarily a matter of love for and appreciation of God; Who even though is Almighty, makes such provision for mankind (Psalm 8:4, Psalm 138:6).

However, fear of God is just as important... after all, He is God! - Jeremiah 10:7, Hebrews 10:31.

Yet, love is key. He is a great, good God Who compassionately cares... (Psalm 145:8-9, Matthew 5:45).

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"For scarcely for a righteous man will one die; yet perhaps for a good man someone would even dare to die. But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us. Much more then, having now been justified by His blood, we shall be saved from wrath through Him." - Romans 5:7-9

"For You, Lord, are good, and ready to forgive, And abundant in mercy to all those who call upon You." - Psalm 86:5

to be honest, NO