When I was in seminary, I listened to a series of sermons by John Piper that he preached and a conference for those who are entering (or have entered it a while ago) the second half of their life. He made a call to them to be counter-cultural in their thinking and to FINISH WELL. I like that concept! I am 32 years and I may have 1 day, 1 month, 1 year, 1 decade or 5 decades left to live--but I want to finish well. I want to be faithful. I want to say with Paul - "I finished my course and fought the good fight of faith."
Whether you are young or old, if you are a disciple of Jesus it is important to think on these things. Here is a sermon by Jerry Bridges (author of The Practice of Godliness) called "Four Essentials to Finishing Well."
You can listen to it, watch or download it.
You can also purchase the series by Piper I mentioned above called "Finishing Well" here.