So, what about this little quote, which is often tossed out to encourage? Does something make us stronger if, indeed, it doesn't kill us? The answer is in the context. What is the situation? Also, what way is it meant to be stronger? If, the situation is a person sick with polo, the result may not be death but it could be to never walk again. Was this person made stronger? Possibly...
Let's take into consideration James 1:2-4, "Consider it all joy, my brethren, when you encounter various trials, 3 knowing that the testing of your faith produces endurance. 4 And let endurance have its perfect result, so that you may be perfect and complete, lacking in nothing." (NASB)
Now what? Is it really, what doesn't kill you makes you stronger?
Answer: Perspective.