Your answer to that question is critical in your life, because in many ways it will dictate your behavior and determine how you spend the time you've been given. Time is both a gracious gift from God and a merciless task master - it is the medium through which we live our lives but also the stern disciplinarian who stands over us with relentless continuance, refusing to slow for any purpose. In fact, it often feels as if time grows increasingly impatient with us as we age and therefore actually speeds up (remember how long summer vacation felt when you were a child)?
I truly love the poem often attributed to Ralph Waldo Emerson:
To laugh often and much;
To win the respect of intelligent people
and the affection of children;
To earn the appreciation of honest critics
and endure the betrayal of false friends;
To appreciate beauty, to find the best in others;
To leave the world a bit better, whether by a healthy child,
a garden patch or a redeemed social condition;
To know even one life has breathed easier because you have lived.
This is to have succeeded.
Beautiful, truly. However, I believe this needs to be paired with the ending of my favorite Bible book, Ecclesiastes:
"Let us hear the conclusion of the whole matter: Fear God and keep his commandments: for this is the whole duty of man. For God shall bring every work into judgment, with every secret thing, whether it be good, or whether it be evil."
Realizing that none of us could withstand such a judgment and therefore must be saved by the Lord Jesus Christ, for we are not "basically good" as the humanist's like to suggest, rather, our hearts are "desperately wicked, who could know [them]?" For "we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others. BUT GOD, who is rich in mercy, for his great love wherewith he loved us, even when we were dead in sins, hath quickened us together with Christ, by grace we are saved."
We must be careful indeed how we define success.