Just how good do you have to be?
Suppose God sets the pass mark for heaven at 100% (heaven is a rather special place after all) and you only get 95% of your life right. 5% is wrong. You haven’t made the grade.
Suppose getting into heaven was like leaping a 10 metre chasm. You might make three or four metres and a desperate world class long jumper given a good run up in the right conditions might make nine. But neither of you makes it because neither of you is good enough, not even the best.
Or suppose your life is like an amazing omelette that you cook up for God. In go the eggs, one, two, three, four, five; so far so good. The last egg is rotten and stinking but you mix it up anyway. The result is very unappealing. Not good enough.
If you only did one bad thing a day you would be pretty special. But by the time you are twenty you’ve got 4,000 indictments on your charge sheet (I didn’t start counting until you were ten) and by the time you get to sixty you’ll have 20,000 sins to answer for. Definitely not good enough for heaven!
In fact no one is good enough. But Jesus is good news for two reasons: he pays the price for our sin by dying in our place on the cross and he makes us right for heaven, even when we are clearly quite unsuited to go there. Jesus offers an amazing identity swap; his perfection for my imperfection, his goodness for my badness. The bible calls it forgiveness and new life.