One of the most beautiful and unique things about our faith in Jesus, especially when you compare our beliefs to those of all of the man-made religions of the world, is that it's just not fair! At least, one could say that it's not fair in terms of its "merit system".
Read what Jesus has to say about who gets to enter heaven in "The Parable of the Laborers in the Vineyard" in today's reading from Matt. 19-20 (ESV)
People of other faiths - Muslims and Mormons, for example - say that they believe in a god/gods who forgive their sins... but the truth is, the deeper you dig, you'll always discover that their gods are only truly forgiving after you've done some kind of good works to earn that forgiveness! So the end result is a pretty "human" god in terms of their expectations of us; a god who's able to forget about your sins as long as you "make it up" to him somehow. But we know that we could never "make up" for even one sin that we've committed before our holy God! A sin is a sin, and it only takes one sin to make us unclean enough that we could never be with God in His holy presence again! And that's where Jesus comes in... His sacrifice and His blood alone have the power to cover our sins so that our holy God never sees them again when He looks at us!
So no matter how long it's taken us to "find our way to the vineyard" and start getting to work... Whether we've spent our lives being as rotten as Adolph Hitler or as pious as Mother Theresa, as long as we ultimately repent of our sins and put our trust in Jesus, things are just not going to be "fair" in the end! At least not by human standards of merit! Because by faith in Jesus, we're all going to receive the same reward in the end - eternal life with our loving God!