Swapping used cars

You have people who convert from Christianity to atheism, or (what often amounts to the same thing) from creationism to evolution, or Calvinism to freewill theism, or Evangelicalism to Catholicism, or inerrancy to "progressive Christianity."  Supposedly they do this because they discover difficulties in their original position.

However, the result of their conversation is to exchange one set of difficulties for another. They are very impatient with their former position. They cut it no slack. 

They make excuses and allowances for their newfound position that they refuse to make for their former position. They emphasize or overemphasize the difficulties of their former position while they underemphasize or deemphasize the difficulties of their new position. The psychology is peculiar. 

Part of the reason is that they know–or think they know–the old better than they new. So they underestimate the difficulties of the new position. They were drawn to its superficial advantages. Only after they get deeper into it do the disadvantages become more prominent. But that then they're committed. It becomes a face-saving issue. 

Positions like atheism, evolution, freewill theism, Catholicism, and "progressive Christianity" have enormous preexisting baggage, It's not like the convert has shed all the intellectual challenges by leaving his old position behind.Rather, he's inherited intellectual challenges that come with his new position. Yet, for some odd reason, the convert regards these difficulties as acceptable difficulties. 

Although it seems counterintuitive, both true and false positions have intellectual difficulties. You might suppose, a priori, that the true position would avoid that. But due to human ignorance and the complexity of reality, even the true position can have significant (apparent) difficulties. 

Given a choice, you might as well stick with the true position and defend the true position, for whatever position you take will be intellectually challenging.