An excerpt from John Ortberg's book, The Life You've Always Wanted (Chapter 3: Training vs Trying pages 57-58)

On the diagnostic side, sin can be divided into two general categories: sins of omission and sins of commission. Sins of omission involve not doing those things we ought to do; sins of commission consist of things we do that we do that we ought to avoid.

Similarly, Dallas Willard notes that spiritual disciplines can be placed in two categories – disciplines of engagement and disciplines of abstinence. Disciplines of engagement involve my intentionally doing certain things. Worship, study, fellowship and giving are all disciplines of engagement, By contrast, disciplines of abstinence involve my intentionally refraining from doing some things. These include practices such as fasting, solitude and silence.

Here's the connection: If I struggle with a sin of commission, I will generally be helped by practicing a discipline of abstinence. In other words, if my problem is that of doing something I ought not to do, I need to practice a discipline that strengthens my “not-doing” muscles. So if you have a problem with boasting (a sin of commission) what disciplines are likely to help? If you said silence or secrecy (both disciplines of abstinence), you're right.

If I struggle with a sin of omission, I will usually be most helped by a discipline of engagement. That is, if my sin involves a failure to love or encourage or serve, I need practices that will help my doing muscles. If, for example, you ever wrestle with joylessness, you will want to immerse yourself in my favorite discipline of all – the discipline of celebration.