Moses wrote Psalm 90 at the end of the forty years of Wilderness Wanderings. It was when the Exodus Generation had passed away as judgment for their sin at Kadesh Barnea.
The application of this psalm for believers today is fourfold. Firstly, we need to recognise that no matter how long we live, from a divine perspective, life is very short. Secondly, not all of our years are going to be productive, and we could be further side-lined through tragedy, illness, and sickness, thus becoming even less productive. Thirdly, we must be very conscious of how much time we have left in this world. And fourthly, we must plan our lives in such a way to be most fruitful for the Lord, doing His work.
Believers often use many sayings and clichés, including some that are not even biblically valid, such as “Let go, let God.” However, based upon this particular psalm, there is one cliché that is truly biblical, and we should make its message real in our lives:
“Only one life ’twill soon be past; only what’s done for Christ will last.”
You can download Ariel Ministries’ full exposition of Psalm 90 from this link: http://www.arielm.org/dcs/pdf/mbs184m.pdf.