Christians believe that all people should strive to live in imitation of Christ; this includes obedience to the Ten Commandments, as interpreted by Christ (as in the Sermon on the Mount). Jesus taught that the greatest commandments were to: “love the Lord thy God with all thy heart, soul, mind, and strength,” and to “love thy neighbor as thyself.” This love includes such injunctions as "feed the hungry" and "shelter the homeless", and applies to friend or enemy alike. Other Christian practice includes acts of piety such as prayer and Bible reading.
Christianity teaches that one can only overcome sin though divine grace: moral and spiritual progress can only occur with God's help through the gift of the Holy Spirit dwelling within the believer. Christians believe that by sharing in Christ's life, death, and resurrection, they die with him to sin and can be resurrected with him to new life.
-- In part from wikipedia.