The thing to remember is that disease is a consequence of sin being a part of this world. And despite the fact the world has such suffering in it, we know God loves us because He allowed sin to go unpunished (for now) so that he could redeem us. Getting rid of all disease would mean getting rid of sin which would mean obliterating each and every one of us now. God is waiting until the time of his own choosing such that all who have been called to repentance come (2 Peter 3:9).
Truthbomb Apologetics: Video: How Could a Good God allow Children to Die of Diseases? featuring J.P. Moreland, Greg Koukl and Craig Hazen