The old thing of, if there is a god, why this, why that..
God can't stop bad people doing bad things, can't stop the world, etc
Believing in Christ, believing in God, gives you the strength to deal with these things. Christianity has moved a long way from blaming God etc
"Cast your burden upon the Lord and He will sustain you;
He will never allow the righteous to be shaken" Psalm 55:2
People are right to question, the bible even shows this.. Religion can't exist without opponents.
"Do not be unequally yoked with unbelievers. For what partnership has righteousness with lawlessness? Or what fellowship has light without Darkness". Corinthians 6:14