smiddy,
To your question "Whether God is concerned about the deaths of Billions of children under 5 years of age and he does nothing?" there is no acceptable answer.
But that does not mean God does not
exist because my experience is that He does exists. This conclusion I made
by observing what is happening within me: Suppose
you went to a shop in a commercial street in the evening, and are having a
dream of it later in the night. And in the dream, you correctly read the name
board of the shop you visited yesterday. However, name boards of the nearby
shop you see in your dream may not match with reality! This means mind simply
recalled what it could and completed the picture with imaginary details (which
obviously means that mind is engaged in some creation work). Not only in dream,
even in real life mind acts in the same manner. Try to remember a big gathering
you attended in the past, and your mind would supply both truth and fabricated
information—picture of some people around you in the gathering will be correct
and others will be mind’s creation. Then there is another interesting
situation. Someone passed a harmful gossip about another, and I passed it to
another. Now unlike we always do, pause for a moment and ask “Why did I do
that?” and listen for the answer. If you put your mind into real silence, it
will tell you: “You passed that harmful information about Mr X because he did
not support your ego sometime back.” From where did come this godly answer? Not
from the mind which joyfully prompted you to pass the gossip in the first
place. But it came from an immaterial part within me which resembles the
Supreme Soul without.