If you remain in me and my words remain in you, ask whatever you wish, and it will be given you. (John 15:7)
What a promise! All we have to do is have faith and ask! Not as simple as it seems.
To remain in his words (or as in the KJV - to abide) means not only to know the word of God, but to have the faith in Christ he desires. This is where we all become like Thomas...we doubt! Again, our human nature gets in the way. So many times I've prayed and had faith that God would deliver to find that during that waiting period (when I get impatient), my faith would sway and I'd think "this isn't gonna happen".
Today, my faith is much stronger. I'm learning to wait on the Lord. I've never been one to wait for anything! In my adult years, I never had to - if I wanted something, I just went out and bought it. But there are some things you cannot buy; some things that are worth waiting for! So today I wait. I continue to pray and ask (and no, I stopped asking for material things long ago) for what I want, applying the need factor (reasons why I want it) and know that if it is in God's will, it will come about. The promise that it will be given to us is guaranteed. Sometimes God gives us things we want only to show us that that wasn't what we wanted and then we say "why did you do that?" We go to him like needy children and think we know what is best for us - we don't see the big picture and we continue to pray for our will, not his! We get on that treadmill and continue to pray over and over again without getting anywhere and say to ourselves "Is he saying 'no' or am I not being patient enough?" When that happens, we have two choices: let the request fall away (give up) or change the request (the intercession of our hearts). If you pray for something long enough, eventually he will enlighten you if you don't get the answer. Continue to pray. He hears you - he's always listening!