The only thing is, you can't do enough good deeds. Here's an analogy that may help you see why...
You're a teenager, so you go to school and know all about grades and how your GPA is calculated. Let's say you wanted to get into a particular university, but the only way you would qualify would be to be admitted would be to complete high school with a 4.0 GPA. Well, let's say you start out pretty strong. In your first semester (or term or whatever you want to call it), you get all A's except for one class, in which you get an A-. Your GPA is now 3.894. Close, but not good enough. So, you resolve to never get anything other than an A again. By the time you graduate, you've managed to do that. You've got dozens and dozens of A's and just that one A- you got right at the start. So what's your GPA? It's 3.99999. It wouldn't matter how many more years you were to continue to go to school and how many more classes you were to take. Your GPA would NEVER be 4.0. And you would NEVER be admitted to the university you wanted to attend.
God does not look upon sin with "the least degree of allowance." That means that 3.99999 is not good enough to get you back to His presence. But, He has provided a way around your problem. He let His perfect Son, Jesus Christ, make up the difference, thereby making it possible for you to return to Him with a perfect score, so to speak. He expects your best, but He knows you can't do it alone. You are a fallible, finite being, and the only way you will be worthy to return to Him is by joining together with a perfect, infinite being. Because what's the sum of a finite, negative number (you) and an infinite, positive number (Christ)? It's an infinite, positive number. I don't know if that makes sense to you or not, but it's just my two cents worth...