If you believe, you will receive whatever you ask for in prayer.
We should be quick to realize that God did not write us a blank check to get anything we want from Him. If someone is not happy, healthy, and successful it does not necessarily mean that they don’t have enough faith.
God absolutely will answer prayers and give us what we ask for if we ask properly in faith. However, what we ask must be in accordance with God’s will.
When we pray, we should always seek to ask for what God wants. This means that our prayers will not be for selfish reasons. We should not expect an answer from a selfish prayer.
There are other times when are prayers are not selfish but for the well being of others. Ultimately we have no way of knowing whether these things are God’s will or not and so we should pray for God’s will to be done.
God may desire for someone to recover from an illness or he may have a greater purpose in allowing the sickness to remain. It is by no means wrong to ask for healing for someone but we should always pray that God’s will would be done in the situation and not just what we would want.
When we pray for God’s will to be accomplished in any situation, we are guaranteed that God will accomplish His purposes in answer to our prayer.