It seems strange but true faith is based on spontaneously giving back to the Lord our free gift of agency. It is pretty clear to me that the greatest gift we can give to the Lord is to lay at His feet our free agency. There is no example more perfect, neither a more perfect connection between faith and our freedom to chose. This is the supreme form of love, respect and obedience, and above all, total faith. When this concept is realized, miracles are the natural results.
Faith is like a muscle.
If it isn't exercised, it will atrophy. But if it is used, it will develop. Since God works for our spiritual salvation, He gives us trials, and trials and troubles are blessings to help us produce the faith necessary for our own personal salvation. Through faith also Sara herself received strength to conceive seed, and was delivered of a child when she was past age, because she judged him faithful who had promised. Therefore sprang there even of one, and him as good as dead, so many as the stars of the sky in multitude, and as the sand which is by the sea shore innumerable.