Why do people lose faith in God?
One of the main reasons people loose faith in God is because of the universal question WHY? Why did God allow this to happen?. Why did not God do this or that. Why does God allow war. If God loves all mankind why...? And so on and so on.
To people of the Jewish faith, certainly. This is a question of faith and naturally those who have faith in God as described by Jewish teachings will claim Him to be True. Those who do not have faith in this God or have faith in a different god or gods will claim Him to be False. Only you can decide which is true.