After reading the Bible, you will become aware that you haved not lived up to the Biblical standards. This is a natural response for no one is able to meet God's righteousness apart from Him "for all have sinned, and come short of the glory of God." Romans 3:23
Still God requires people to turn from their sins to Him. Repentance is the desire and willingness to change the direction of our lives. Mark 2:17 and Acts 3:19 show the necessity for repentance.
Changes are needed but fortunately, He does not expect us to succeed without His help or our faith. Roman 1:17 says that "the just shall live by faith" which is a living faith that overcomes weaknesses through belief in the power of God. This doesn't mean that the Christian walk is going to be easy, for you will continue to struggle against sinful desires but after becoming a Christian, a faithful dependance, a willingness to follow and a belief in His mercy will ensure eventual victory. We will never be perfect but instead there will be a process of being transformed or perfected by God's Word. 2Thessalonians 5:23-24
"O wretched man that I am! Who shall deliver me from the body of this death? I thank God through Jesus Christ our Lord. " Romans7:24-25