Mark 11:24 - "Therefore I tell you, whatever you ask for in prayer, believe that you have received it and it will be yours."
Pondering this passage, one might think that this statement by Jesus states that if you pray for anything, you will receive it at some point in the near or possible distant future. However, often times our prayers aren't answered the way we ask them to be and therefore we question this kind of declaration. Perhaps, it's Jesus wanting us to not only practice our prayer life, but to recognize that in the moment of that prayerful time, we find peace and contentment in the notion of our confidence in God's ability to accomplish all things possible with an incredible level of ease no matter how difficult the request is.
When God does answer our prayers, they are free gifts of mercy because it was Jesus that died for our sins and that sacrifice by our Lord, laid the foundation for us which allowed us to ask in prayer for things, but ultimately, it's always God's will.
God just wants us to direct all things to him and he looks for our commitment to do so, which means being consistent and obedient in our attempts to be whole with him. We are all sinners and as such, he forgives us, but I believe what he wants more than anything, is for us to pray for things that are in alignment with God's will and then by believing that you will receive it, the understanding is, it will be yours.