" Our assurance is quite different in kind from scientific knowledge. It is born out of our personal relation to the other parties; not from knowing things about them but from knowing them.
Our assurance—if we reach an assurance—that God always hears and sometimes grants our prayers, and that apparent grantings are not merely fortuitous, can only come in the same sort of way. There can be no question of tabulating successes and failures and trying to decide whether the successes are too numerous to be accounted for by chance. Those who best know a man best know whether, when he did what they asked, he did it because they asked. "

― C.S. Lewis , The World's Last Night: And Other Essays