Q: At any given moment there are millions of people praying to God. How is it possible for God to pay attention to my little, silent prayer amidst all the chatter?
The reason you or I can only effectively listen to one person at a time is because we only have a limited amount of attention to spread around, due to our limited brain power. If two people are talking to us at the same time, we have to divide our limited attention between the two, which means we can’t attend to either person very effectively. But God does not have limited brain power or limited attention. In fact, he has infinite (unlimited) brain power and attention. Since you can’t fraction infinity (a third of infinity is still infinite), this means that God can listen to each and every one of a trillion people talking to him as though EACH ONE were the ONLY one. He doesn’t have to spread his attention thin to cover all the individual prayers.
So, when you talk to God you rest assured that ALL his attention is on you, as though you were the only person he created. It’s just that, being the great God that he is, the same is true for each of the other million people talking to him at that very same moment.