If I had to pick one thing that bothers me about Christians/the Church/Christendom today, it's our lack of drive to be the absolute best. We ought to strive for nothing less than excellence in all of our endeavours. We are a reflection of the God we serve, and looking around at God's reflectors here in America, God seems pretty, well, lousy.
Jesus asks us to function as lights to society, so that they can "see our good deeds and give honor to our Father in heaven." Furthermore, in I Corinthians Paul said that we should do everything for God's glory.
If God is really so great (not to mention real) why aren't His followers great? Why aren't we producing the most talented music, running the most successful businesses, building the most efficient houses, writing the most brilliant books, developing the most advanced technology, and altogether running circles around the competition?
To make matters worse, we hypocritically condemn the "secular" pursuits of the world, only to capitalize on their developments. We use cell phones, drive cars, shop at stores, watch TV, take medication, live in houses, and enjoy other such "worldly" creations. Basically, we mooch off of society's advancements, all the while touting an I-only-pursue-God-and-I-don't-waste-my-time-on-temporary-pleasures-because-I-am-so-spiritual attitude.
We tell ourselves that anything other than Bible study and prayer is somehow un-spiritual, and so we don't pursue our interests with excellence (i.e. we aren't good "contributors to society"). If it's worth doing, it's worth doing well. If you think it would be a waste of time to perform something you do with anything short of excellence, you are wasting your time. God has given us dominion over this world, and has asked us to bring honor and glory to His reputation. We are supposed to be making God famous. People should watch what we do, and see the glory of God. God has saved us from an old life of bondage to sin, and brought us into a new life of bondage to Him. We have been brought from death to life. We should want to please God, by doing our absolute best for Him. Anything else damages the reputation of God.
The problem comes when I look in the mirror. Am I an excellent writer? researcher? assistant manager? citizen? church member? husband? Do I contribute something worthwhile to others, or just leach off of other's accomplishments?
Truth is, I'm a pretty mediocre guy. Maybe the problem isn't other Christians. Maybe the problem is me.