Do vs Done
You need to recognise the difference between Christianity and religion. You see, a lot of people think they are the same thing but they are not.
Religion is spelt DO, because it consists of the things people do to try to somehow gain Gods forgiveness and favour. The problem is, you can never know when you've done enough. It's like being a salesman who knows he must meet a quota but doesn't know what it is. Worse yet, the Bible tells us in Romans 3.23 that we can never do enough. We will always fall short of Gods perfect standard. Thankfully that's not all.
Christianity however is spelt DONE, which means what we could never have done for ourselves, Jesus Christ has already done for us. He lived the perfect life we could never live, and He willingly died on the cross to pay the penalty we owed for the wrongs we've done. A real Christian is someone who has trusted in what Christ has done on their behalf, freeing them from religion and assuring them of Gods love, forgiveness and aid in their life.