How do we overcome our fleshly attraction to the things of the world? The answer is simple: We overcome the world by our faith. And by faith, John means obeying God’s commands (1 John 5:3). 

There are two stages to our overcoming the world through faith. The first is when we put our faith in Christ, overcoming Satan’s desire to keep us from yielding to God (“has overcome”—past tense). The second is when we continue to obey God and His commands by faith (“overcomes”—present tense). These two tenses in 1 John 5:4-5—past and present—represent the beginning and continuation of our overcoming the world. First, we obey God by putting our faith in Christ. Second, we continue to obey God as we follow Christ as Lord of our life. By obeying God, we overcome the world.

If you find yourself yielding to the temptations of the world, look for an area in which you are failing to obey God.

If I could simplify the Christian life to one thing, it would be obedience.
John MacArthur