Wow! We so have to believe that God can and that God will do what He promises! Moses told God that he could not speak, that he was not a good speaker, God told Moses he would give him the words. When the time came Moses opened His mouth believing and God had given him the words. If Moses had not opened His mouth he would have never known if God kept His promise.
God gives us free will. God's promises are always there for us, always. We just have to make the choice to use those promises. We have to have the faith to draw on those promises and know that they are there for us. We can not have faith in God's promises if we do not know what they are. But, even if we now what they are if we do not believe that God will keep those promises for us as individuals, if I don't believe that God will keep that promises for me, Jeannie Phillips then we won't call on God's promises when we need too... If we don't do the if God can't do the then.
When I am missing out on God's promises to me, it is not that God is not there. If I am missing out it is because I have not believed God enought, my faith is not strong enough that I have given that part of my life to God. I never need to ask God, "Where are you?" I need to say to God, "Grow may faith, help me believe in what you promise!"