I believe the reason for pain and suffering is because if life on earth was a wonderfull paradise there would be no reason for heaven. the reason for our being possibly might be because he wants us to have a choice to. To prove to the devil,his angels,and to us humans that loving him is an option not a requirement.  I too don't like knowing people all around the world are enduring tragic pain either but when our time is up for life on earth all how are worthy will be greeted with an ultimate prize, the glory of god in person.