Although we may have graduated from high school, college, or university, we, from a spiritual point of view, are still in need of much education. That is why Moses presents to us in Psalm 90:12 this prayer: "So teach us to number our days, that we may apply our hearts to wisdom."
He does not write this to little children. He is not exhorting a few people here and there. Notice that he uses the pronouns "we" and "our." Plainly then he includes himself. We all need to number our days and set our hearts on wisdom.
The reason why we must count our days is that, after they are ended, we go to God's house and dwell with Him in covenant fellowship; or we go to hell to be with Satan and his host in everlasting punishment. Therefore we must count our days so that we may apply our hearts to wisdom.
Now wisdom is more than knowledge. We may know that we will soon go the way of all flesh, and yet walk unwisely. To act wisely is to choose the best means to reach the highest possible goal. And the best means is trust in Christ, believing that He earned a place for us in heavenly glory. By all means we must consider such dwelling with God to be the most wonderful blessedness for man.
In wisdom then we must be seeking that kingdom. In wisdom we must strive to live as its citizens in all we say and do. It will be wise for us to read and study God's Word. Wisdom will move our hearts to go to God's house every Lord's day to hear His word proclaimed about this kingdom and the way which He prepared for us to enter.
Wisdom will cause us to reject sin, and fight to keep it out of our lives. Wisdom will cause us to put all our trust in what Christ did, and will cause our hearts to beat with thankfulness to God for having prepared the way for us to enter. Wisdom will put our trust in God.
Read: Psalm 90
Quote for Reflection:
By a faithful oabservance of Family-Worship, you will be employing a daily means towards the eternal salvation of your household. No prayers, indeed, considered as so much work wrought, will effectually save those souls; but we know no means which tend more directly to this end, than domestic worship, and the duties to which it leads. Are you willing to hazard so great a neglect? ....Family-prayer is a duty of every householder, binding on him every day of his life.... Fly at once, with your household, to the throne of grace! Cease to consider it as a matter of indifference, or an affair of variable custom. The neglect is most serious. It is your loss,and the loss of your offspring.
--James W. Alexander, "Thoughts on Family Worship"