2 Corinthians 10:12-18

v12-14: When comparing ourselves with other Christians we must take care.  Whilst comparing ourselves "with others who outshine us would be a good method to keep us humble" and to spur us on to grow in godliness, there is a real danger that it leads to pride and arrogantly thinking we are better they are.

v15-18: To boast about our godliness or gifting "is often as foolish and vain as it is proud," because any progress or success has been given to us by God.  We should be pleased and thankful for what we have been given but the praise and glory must all go to God.