"If Christ is not made much of in our lives, they are wasted. We exist to make him appear in the world as what he really is—magnificent. If our life and death do not show the worth and wonder of Jesus, they are wasted." -John Piper
We waste our lives when we live for our glory rather than the glory of Christ. We waste our lives when we store up treasures on earth and live for the fleeting pleasures of this life. We waste our lives when we do not love others by pointing them to the cross. We waste our lives when we do not carry our cross and follow the Lord, regardless of the cost.
The wasted life is really the wasted day. If we are not to waste our lives, we must not waste our days. Living for Christ's glory and His Kingdom does not start after graduation, after we have a family or at some other distant point in the future. Living for Christ's glory starts now. It starts today. If we are not to waste our lives, we must not waste our days.
"Then he said to them all: "If anyone would come after me, he must deny himself and take up his cross daily and follow me." -Luke 9:23
"Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own." -Matthew 6:34