Let's imagine for a moment that living a good life will get you to heaven someday. All the charitable giving you've done, all the volunteer hours, all the niceties to strangers, all the service of loved ones - all of this accumulates over a lifetime and when you breathe your last, you enter heaven.
As you think about your life - the good life you've lived - have you been good enough?
You might say, "Well, I think so." Or "I hope so."
How? How do you know you've been good enough? Are you sure the standard for charitable giving isn't 5% higher than what you have given? Are you sure the standard for volunteer hours isn't 10% higher than what you've done? How do you know you've given strangers enough niceness for God to let you enter his kingdom? How do you know?
For the person who believes living a good life is enough to warrant entry into heaven, the above questions are a big problem. Why? Because there are no clear answers to those questions. None! So if you're holding your breath hoping the life you've lived will be good enough, I want to offer you a different way of thinking about this.
The cross plays a significant role within biblical Christianity for a reason: it shows us the results of our best efforts at a life well-lived. Even the most pious among us fall short of God's acceptance. Consider this: if we could gain entry into heaven by living good lives, why did Jesus have to leave heaven, come to earth, and die? It doesn't make any sense, unless the best we could achieve on our own came up woefully short.
Your best good works still come up woefully short of earning God's approval. That's why we have Jesus. Jesus lived the life you could never live and earned God's acceptance for it. Jesus also died the death your imperfect life deserved. When you say to God, "God, I can't earn salvation. I'll never be good enough. But I know Jesus has done everything for me. I want to trust him and follow him" - the moment you say that to God, a significant event takes place: God adopts as you as one of his children. Heaven awaits you.