I know a fervent theist and when he meets you his first words are " Hello I'm a Christian ! " and a few years ago his wife was diagnosed with cancer . She was admitted to hospital where the growth was removed and he prayed fervently for her recovery. It was successful and he claimed it was his prayers that were the main reason. Which he proceeded to tell everyone whom he met as positive proof of the power of prayer. However a year later the cancer came back with a vengeance and despite more fervent praying for her recovery she died within a month.
Now you would think that whatever his beliefs that would have shaken them , but no, he was more fervent than ever. He now claims all his prayers had been answered, she was now " In the arms of Jesus in a far better place ".
I should add he had the vicar , all the congregation of his church , plus a bible group who meet up during the week , adding their prayers and support . Result ! Nothing apart from giving him some solice.