I believe I've asked this question before on hubpages, as well as answered it, but its definitely a good one that many of us have pondered on.
Life to me presents obstacles and challenges from many directions, and in many ways or forms. Say the physical barriers that separate most humans from achieving certain goals, or blocking one from movement. There's the mental one's that attempt to inspire fear, or instability, and possibly mind control of people. Then there's spiritual barriers as well in life that aren't as obvious, and definitively will show themselves throughout the countless moments in human existence, in the struggles for dominion and balance of things in religious ways or non religious ways as well.
With all that being stated, to counter such barriers in life to me takes the full out living of life, without regard to being stopped by such barriers in their present, past, and future forms of existence. By being able to bend around such things, or adapt to inherent situations of a forced nature or that from an outside influence.
If done with the right measure of judgement and care, a person can learn to enjoy this life we have, the full beautiful nature that truly exists for our souls to feed off of and enjoy & to share with many others their travels upon this precious planet, instead of forcefully lashing out of fears, and desires to take ownership of it all for mere greedy pleasurable filth.
So basically put, life is what you choose to make it for oneself, life is what you choose to accept from others, and life is how you live it all out based on ones perception of the usefulness of such. It can also be seen as ones full assessment of the totality of their environment & its overall effects on themselves as well as others. Without sharing, giving, loving, and providing for others for some reason life seems to become meaningless in my opinion, whether your a firm believer in something or not.
Thanks for sharing yet a great universal question that hits everyone of us at home base sort of speak, & countless philosophers, religious leaders, some politicians, scientists all have attempted to answer for us all.