Repentance for our faults and "foibles"

According to John Newton, most Christians generally avoid committing the most gross sins. However, he argues many never actually achieve much in the way of spiritual growth because they coast on their strengths and do little about their weaknesses, robbing both themselves and others of joy whilst simultaneously failing to bring glory to God. Worse still, Newton argues, those who harbour such behaviours self-justify them as mere "foibles" because they "may not seem to violate any express command of Scripture". Nevertheless, Newton comments these behaviour are "properly sinful" because they are the opposite of the fruits of the spirit the Christian is supposed to exhibit.

Tim Keller, taking a lead from Newton, argues that such behaviours mean "large swaths of the Christian population have little influence on others for Christ. While our faults always seem small to us due to the natural self-justification of the heart, you can be sure they don't look so small to others".

Newton offered a list of specific examples of those who act in such ways in Blemishes in Christian Character. Tim Keller, following Newton's example, has also created a similar list which is useful for self-examination (also found here). Here are some things we should look to stamp out if we see them in ourselves:

Austerus is a solid and disciplined Christian but abrasive, critical, and ungenerous in dealing with people, temperamental, seldom giving compliments and praise, and almost never gentle.

Infitialis is a person of careful and deliberate character but habitually cynical, negative, and pessimistic, always discouraging ("that will never work"), unsupportive, and vaguely unhappy.

Pulsus is passionate, yes, but also impulsive and impatient, not thinking things out, speaking too soon, always quick to complain and lodge a protest, often needs to apologize for rash statements.

Querulus is a person of strong convictions, but known to be opinionated, a poor listener, argumentative, not very teachable, and slow to admit wrong.

Subjectio is a resourceful and ambitious person, but also someone who often shades the truth, puts a lot of spin on things (close to misrepresentation), is very partisan, self-promoting, and turf-conscious.

Potestas gets things done but needs to control every situation, has trouble sharing power, has a need to do everything him or herself, and is very suspicious and mistrustful of others.

Fragilis is friendly and seeks friends, but constantly gets feelings hurt, easily feels slighted and put down, is often offended and upset by real and imagined criticism by others.

Curiosus is sociable but enjoys knowing negative things about people, finds ways of passing the news on, may divulge confidences, and enjoys confronting too much.

Volatilis is kind-hearted and eager to help, but simply not reliable—isn't punctual, doesn't follow through on promises, always over-extended, and as a result may do shoddy work.

As Keller helpfully says "Look at these and ask which one or two most describe you. Have the courage to ask someone else you know, too... look both at why so many of us seem to be stuck in these character flaws instead of growing and changing to be of more godly character".