God knows what is best for us

n every life, no state had always walked like what we expect. Sometimes, we are disappointed with what has happened. disappointed why our desires, our prayers as if God did not pay attention. In fact .., I think we've always begged, prayed and worked hard to achieve our desires. But why have not you give it? Is it true that not all of us deserve God's desire to give? If it is true, then God knows what is best for us.