There Are Things Worse Than Sexual Immorality

Here is the final paragraph from C.S. Lewis's chapter on Sexual Morality in Mere Christianity. Brackets are mine. All else is his.

"Finally, though I have had to speak at some length about sex, I want to make it as clear as I possibly can that the centre of Christian morality is not here. If anyone thinks that Christians regard unchastity [sexual immorality] as the supreme vice, he is quite wrong. The sins of the flesh are bad, but they are the least bad of all sins. All the worst pleasures are purely spiritual: the pleasure of putting people in the wrong, of bossing and patronising and spoiling sport, and backbiting, the pleasures of power, of hatred. For there are two things inside of me, competing with the human self which I must try to become. They are the Animal self [sins of the flesh], and the Diabolical self. The Diabolical self is the worse of the two. That is why a cold, self righteous prig who goes regularly to church may be far nearer to hell than a prostitute. But, of course, it is better to be neither."

The Lust for Leadership

Peter Leithart commenting on Diotrephes in III John 1:9-10 in his book From Behind the Veil. 

Though the specific situation of Gaius' church is not replicated in every church, the threat of prideful members and leaders like Diotrephes is a perpetual threat. John instructs churches of all times to pay attention and watch out for men in the church who lust for leadership. Watch out for the ambitious man. Watch out for men who refuse to bow to authority, take advice and counsel, resist necessary rebukes and exhortations. Watch out for the men and women in the church who fill the church with gossip and evil words about the leaders in the church. Watch out for people John says, who refuse to receive brothers, who close themselves off from Christians who are not part of the in group. Watch out for these Judaizing tendencies. 

 This is all the product of pride, of wishing to be first, and it destroys the fellowship of the church. This is evil conduct of the most serious nature. If we are going to be judged by how we treat the "least of these my brothers," then we had better be very careful to avoid pride, ambition, gossip, slander, evil words, and resistance to counsel. We ought instead to be cultivating humility, service, edifying speech, and submission to the authority of those set over us.