Only Christ can get us in.
There is only one thing we can do to impact our standing with God and our ability to enter heaven. That is to trust Christ. Romans 3:23 tells us that we all fall short of the glory of God. Because we all fall short, we are not perfect. If we are not perfect then there is nothing we can do to make ourselves perfect once again, because we will always have that blemish on our record. Just as if you mix the ingredients for bread together, you can never get those ingredients back as they were before being mixed together. We live 'under' the law, the 10 commandments. There is nothing we can do under the law to make us perfect because it is that very law that makes us imperfect. Romans 3:20: Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin. The law was given to us to show that we are sinful and that there is nothing we can do to make ourselves perfect. Galatians 3:24 Therefore the law was out tutor to bring us