Why assume that it is God who puts obstacles in front of you? How would that serve His purposes at all? Whose purposes would be served by placing obstacles that cause you to lose your faith? Maybe that's the one placing the obstacles. Don't give up. Reach out to God and ask Him to help you find your way through.

There also times when what we ask for and what we think we want isn't the best thing for us, no matter how much we want it. There are times when we have to have faith that God knows what He is doing when the answer is "no," just like when your five-year-old wants a toy made for much older kids and would be dangerous for him to play with. God can see what would happen if we got what we wanted much more clearly than we can. Sometimes He lets us have our way so that we can learn from the consequences, even though we don't like them. Sometimes we need to ask Him to help us understand.