Non believers are always scared to die and can't digest the truth, they always wants the easy life, so they won't believe no matter what, but the light of Allah cannot be extinguished, they themselves are so frustrated of how they live, they have no light inside them, so won't believe, but if they want to they can make a red flower yellow with their tongues, but Islam is protected by Allah from these lies and it will remain protected till the end of time. The proverb is clear and so true, people just can't face the truth.