Why some prayers are not answered

The following question was printed in the Catholic News:
Question:
Our 26-year old daughter died a year ago after a 15-month bout with oral cancer. I really believed in the power of prayer. My confessor urged me to pray without ceasing, which I did. She was also included in lots of prayer chains. But she never had any good news. When it became evident she would die, I stopped praying. Since then I can't pray for anything because I don't think it will do any good. Can you please tell me why I should pray?

My Answer
Many of us are perplexed why God did not answer their fervent sincere prayers.

The ANSWER is actually very simple. God answer all your prayers that are prayed according to His will.

If your prayers are not according to His will, then sometimes He answers, but mostly, He does not answer.

Jesus knew what His mission on Earth is - to die on the cross as a sacrifice for man's sins. But being human, he agonised over this mission that He was to suffer. So He prayed and plead "Father if Thou are willing, remove this cup from Me..." He knew that this request is NOT according to God's will. So He added "Yet not My will, but Thine will be done." (Luk 22:42)

The second part of his prayer was answered, that is, God's will was done.

Hence, why did God not answer prayers for safety, for healing from deadly illnesses, for the impending deadly tornado to vanish? It's because such prayers are not according to God's will. God's will does not interfere with the natural order of things on Earth.