"Only one life, 'twill soon be past,
Only what's done for Christ will last.

We need to always keep eternity in our minds. Don't be so distracted by the affairs of this world that you forget that you will live into eternity and this life on earth is just a dot in time. I know this is hard to truly comprehend - at least it is for me - but always evaluate what you are doing in the light of eternity. Work and school are important, but it is your relationship to the Lord and to his people and those who don't yet know Him that is truly important and that is where you want to invest you efforts. God has made us to glorify and enjoy Him. Enjoy Him through his creation, including those whom you love, and glorify Him by your words and deeds.