While many religions do emphasize purity and good works, Christianity is having a one-on-one relationship with God.
With a one-on-one relationship with Jesus, He changes us from the inside out.
So it is not just externally "do this" or "don't do that", but it is about knowing God and interacting with Him personally. He also empowers Christians to change from the heart. For example, forgiving people from the heart and loving from the heart.
Also, Jesus came and lived a perfect life. Then He died for our sins as our substitute. So what humans can never do (i.e. be perfect), Jesus did. When a person believes in Him, what Jesus did is credited to that person. So that person is righteous in God's eyes because of what Jesus did for him.
However, this does not mean we take Jesus' death for us as a license to sin. That would be disrespecting Jesus' blood. So the life we live, as Christians, we live to Jesus. With God's help and our diligence, we live a life pleasing to God to glorify Him.
Finally, after we die physically, we can be with God in heaven and live eternally in glory and joy.