It's kind of like you never give your teeth a second thought until you get a tooth ache. You never realize how much you may use a finger until it gets burned or has something that's causing it pain. This is when you pay attention to these things.
The same goes for God, it is easier to almost forget about God in good times and in bad times we either pray to him or sometimes curse at him.
I'm not particularly religious myself, but I have talked to many that are. I met a man from India and he told me something I had never really thought about. He said "You must always thank God" I said "Oh yea when things are good for sure" and he replied "No. You thank him when times are bad, you thank him when times are good - You always must thank him for this life" I don't know if that comes from a book or if it was off the top of his head, but it makes a lot of sense even to me.
Dear, I know the answer might hurt your feelings but the truth is ,Every religion was created by the human beings them self, according to them and how useful the religion could be for them. For example- If while following one religion if some humans found out than this religion, say for example is restricting them , not to eat meat. They created another religion which might allow them to do as they wanted. Just like that you might see that there are various sub-division in hindu and other religion also. Second thing, the so called god's ,you will find thousand of them, were also human beings who created fear and also expectations in the mind of other human beings to create there stands, and it was followed through generations and today still majority of humans are doing it.
There is only one God .now that said you must be seeing the wrong christians or you are not around them long enough to see when they really do think/thank God for anything and everything they have or don't have. Hang around some christians that know what God and his promises are really about and you will see people that think/thank God in the bad and the good situations of life.you just have to look a little harder/closer and pay a little more attention and you will see this statement in your question does not hold true for all christians/and the jewish people God's chosen people. I don't think God has let me down at any time in my life .I may not have seen the outcome he has planned or the plan he has for the long run/eternity but he has always kept his word. It 's quite amazing to see when he does things and other people are baffled how it comes about in order to happen when it should have never happened in theri life the way they view it when it does happen. In other words God does not run away when something bad happens in your life and is not responsible for most of the decisions people/even christians and the jews make wrong decisions and take the wrong path to get what they think should be theirs or they want/desire.so then they turn in a fit of anger or disbelief god let them do what was going to harm them or cause them a problem in life. I like the old story everyone knows.the parent tells their child not to stick their hand in a fan while it's turned on .now the child has benn warned but they do it anyway and find it either has hurt them or taken the skin off the tips of their finger s before they could remove it from the fan . And the first thign they do is runs to whom/the parent that warned them. The same thing happens with christians/jews that have not learned to listen honor God and live by his rules/teachings. They forget to have a relationship with god by reading his word or talking to him /or praying to him then they wonder why hings start happening /or going wrong when they start walking away from the God that died for them . God never promised us a perfect life(it will rain on the just and the unjust) and some forget this. Let's put it this way I would rather go through the hard times with the comforter/God/Jesus than turning and blaming him/getting upset/angry towards him and trying to go it alone. It just doesn't make in good sense . Even Jesus tells us Gods will be done even when he was about to go through the pain of the crucifixion. He knew it wasn't going to be any fun by any stretch of the imagination but it had to be done.in other words even in this he acknowledged God. Some christians and jews (and I am not using jews in a derogatory manner).just have not lived through a storm yet or have not been made to grow within themselves to understand God has a plan ,it may not be our plan but his plan and he has every step layed out for us if we stay in his presence/pray for guidance/help/direction.I know some don't believe and that is the whole problem they seem to forget how and when they were first saved or committed themself to God. Now back to the original question God uses these situations to draw his children closer to him ,helping them remember who he is and what he has done for them and what his promises are to them.sometimes it takes a smack in the nugget(head/brain/something going wrong) to get the attention of some people. : ). Sometimes the rug has to be pulled out from under them so they will remember to look up and talk to their heavenly father. God has to smack me around(strike that reverse it.has let me be smacked around by life) a lot to teach me these things. No ones perfect and it takes some tutoring if you will to learn God wasn't the one that ran the other direction or made these things go wrong....I can go on and on but I'll quit now.: )