There is no success without failure. This is not (just) my opinion, but a natural fact. I would even argue it is Universal Law.
The only major difference between those that succeed and those that do not, are their approach and attitude towards the inevitable challenges they're faced with. (Obviously other factors, such as persistence and hard work come in to play, but the point still remains.)
Much like working out at the gym; muscle cannot be built without resistance-growth in life requires the same. Success and failure are, in effect, two sides of the same coin. Where most give up, others keep going. No matter the challenge, no matter the obstacle, those who continue on are the ones that fortune will favor. For, even in failure, there is always a valuable lesson to which to learn and grow from.
Therefore, it would seem that failure is not only unavoidable, but absolutely necessary to fully appreciate the fruits of success. I do not say this in hopes that one may seek out unfavorable conditions when resources are available, I just simply mean to say: "If at first you don't succeed, try, try again." - And never give up :-)
This is a short snippet I like to view whenever I need a jolt of motivation.- Enjoy.