They spoke against God;
they said, “Can God really
spread a table in the wilderness?
True, he struck the rock,
and water gushed out,
streams flowed abundantly,
but can he also give us bread?
Can he supply meat for his people?”
We do not like to admit it but more are the moments when we doubt God than the times when we believe him. We know perfectly what are the promises that God has given us but we’re not really sure when he will meet them of if they will come to pass at all. When we see that some of the promises of God are not becoming a reality in our lives we wonder: Maybe that promise is not for me? Could it be that I’m doing something wrong that keeps this promise from being fulfilled? Has God forgotten that I exist? Can God really bring out those wonderful things he has promised? and many other questions like that. Just as faith pleases God, grumbling and complaining displeases him. We must realize that our responsibility is to believe and we can not expect to receive blessings and to see results without having done our part of exercising our faith in full. James, the brother of the Lord Jesus put it this way: “If any of you lacks wisdom, you should ask God, who gives generously to all without finding fault, and it will be given to you. But when you ask, you must believe and not doubt, because the one who doubts is like a wave of the sea, blown and tossed by the wind. That person should not expect to receive anything from the Lord. Such a person is double-minded and unstable in all they do.” 
In matters of faith we need much patience to prevent doubt cast by our enemy from entering our minds. In any case, by grace, God’s plan will be fulfilled in spite of our doubts, griping and complaining, but it is better to have faith as we are the main beneficiaries when we exercise faith, even if the promises are not fulfilled in our lifetime. Enough of doubt and griping! Let us exercise our faith! To God alone be the glory! James 1:5-8