14 And we are confident that he hears us whenever we ask for anything that pleases him. 15 And since we know he hears us when we make our requests, we also know that he will give us what we ask for. — 1 John 5:14, 15 NLT
I believe God has obligated Himself to answer every prayer that a Christian prays. I also believe that He does answer every prayer in one of four ways: Yes, No, Wait or gives a completely different answer than we expected and we don’t recognize the event(s) as the answer. It would be foolish to think that God would give a positive answer to any request that required Him to violate His own Word or to give us something that would not be the best for us. Just as parents, we realize that our kids often ask for things that aren’t good for them and we have to say “no”, how much better does our heavenly Father understand and know what is best for us. His great love for us requires Him to only give us His best. The words we use or the format of the prayer are not the important things. What is important is whether or not we have un-confessed sin in our lives. Sin separates us from God and moves us from His umbrella of protection. How much faith is required? I believe that if we have enough faith to ask God for something, that is enough faith. God has made precious promises to His children and He has never failed in doing exactly what He said He would do. The fulfillment of those promises is based on His faithfulness, not ours.
32 He who did not spare his own Son, but gave him up for us all—how will he not also, along with him, graciously give us all things? — Romans 8:32 NIV