Living in harmony with one another is one of many characteristics of the Christian life. But this is easier said (or easier read) than done. This principle requires us to have a right "thinking" about ourselves and each other.
The one who thinks to highly of himself, becomes prideful, conceited, and puffed up. The "know it all" is controversial in his conversations, always trying to prove himself right. This personality does not lead to harmony.
On the other end of the spectrum, you can think to lowly of yourself, wallowing in the insecurity of a low self esteem. This mentality also doesn't stimulate harmony as one remains self-reflective on his or hers faults.
But to live in harmony with others doesn't only require right thinking about yourself, it requires right thinking about others also. You can think to highly of some, placing them as idols in your life, and you can view others as lower than yourself, both of which also do not promote harmony among people.
Living in harmony requires right thinking and right thinking only comes from 1 person, Jesus.
To learn more, listen here:
http://www.midtownchurchfl.org/living-wisely/
