Assumption 1: Some god/gods exists and he created the universe.
Assumption 2: That god is omnipotent. He can do anything.
Assumption 3: That god is omniscient. He knows everything – past, present and future.
So a god created humans and he knows what each of them is going to do. So if a human kills another human, god knew it all beforehand. Since the god is all powerful it must that’s how he wanted things to go. So essentially we humans are just characters acting according to a script – for god’s entertainment presumably. So what’s the point of praying? If everything is predefined, how is your praying going to change it? And you think the god will just change the script because you request him to do so? And since god is omniscient he ought to know you were going to pray for it. Well then it means the act of prayer itself is scripted! So the god puts you in a tight situation, makes you pray to himself and then bails you out – all according to a well crafted plan.
Looks like this god dude was getting bored, so he created a world full of creates who would endlessly go on praising and praying to him – just to massage his ego! Classic example of a narcissist psychopath who likes to surround himself with an army of sycophants.
So if you believe assumption 1 above to be true, just think of what and whom you are praying to.