Paul is perfectly (and for some, painfully) clear about a Christian's ability to forsake what is wrong and to embrace what is right. He wrote something like this to the church in Corinth, "Every temptation you encounter is common to the human race. And God who is faithful, will not allow you to be tempted beyond what you are able to resist. In fact, with every temptation He himself will provide you a way to escape, so that you will be able to endure/avoid it."
Bob Newhart's psychologist may not have the right tone and demeanor, but he is spot-on in his message - at least for believers. Enjoy (or I'll bury you in a box.)