The description of lukewarm (Revelation 3:14-16) identifies someone who is neither hot nor cold. They are neither moving forward or backward. The motivation is neutral. Their course is undetermined and stationary. God describes being lukewarm as sickening. It gives God no pleasure.
Ephesians 2:8-10 says we are created for good works. God makes it evident that He expects us to live for Him because He created us to live. Just as a dark room is affected when light is introduced into it, so should our lives be in a world of darkness. An uncommitted life, one that neither illuminates Christ in our life, nor supports the evil that exists in our world, does not glorify or hurt God ... Right?
Often, we sit back and look at society and conclude that their problems are their own fault. They brought the problems on themselves. As long as their problems don't affect me, they can do whatever they want. Did Jesus come into the world to save no one but me? Or did he come into this world for all mankind?
Jesus came into the world to make a difference. His very nature showed God's intention to redeem a lost people. In Luke 15, there are three stories that show the importance of one soul, one coin, and one son to God. God shows to what great lengths He will go to redeem man, and make a difference through Jesus.
Salt by nature makes a difference in whatever it touches. If it ceases to preserve or stops enhancing flavor, it ceases being useful and is to be thrown away.
Can I make a difference?
To minimize the importance that any one individual can accomplish in God's kingdom would be like the foot saying to the hand, "You are of less importance that I am because you can't run." Or the eyes saying to the nose, "You are of lesser importance than me because you cannot see.