Christians must constantly seek the goal of maturity in Christ. Even the apostle Paul knew that he had not attained the goal so, "he pressed on" to grow in Christ.
A key to that growth is: "forgetting those things which are behind and reaching forward to those things which are ahead". Past sins have been covered and should not hinder us once they are forgiven, and past worldly accomplishments really mean nothing. We are "heavenly citizens in training". So forget about the past and those things that brought you down. The thing that really matters is walking with Christ through life, allowing Him to prepare you for that which is to come.
From My Heart To Yours,