Many are forced to stop drinking alcohol or smoking due to health problems. Some of them stop but return to the old habits after they recover health though they have the knowledge of the harmful effects. Christians are taught not to love the world but to love God (1 John 2:15-16). So, they stop pursuing worldly pleasure but some of them do so unwillingly from a sense of duty. Then, they may return to their old habits at some point as well. However, when they feel the love of God from the depth of heart, it will be different. With love for God, they will be able to keep casting off sins easily and lead a happy life in the Word all the time. "For this is the love of God, that we keep His commandments; and His commandments are not burdensome" (1 John 5:3).