'Honor your father and mother.' --Exodus 20:12
'There is a friend who sticks closer than a brother.' --Proverbs 18:24
According to what 'they say', familiarity breeds contempt ('you know what they say...'). And I suppose that in most senses they are fairly close with this assessment. The more we get to know someone, the more we see things we didn't like and at first either didn't see or didn't want to see.
But if this truism were really true, then one would expect to see families blowing up all over the place. There are definitely too many 'dysfunctional' families, in which relationships are strained, communication blocked, and occasionally outright hostility manifested in frequent visits by the local police. Yet if it were true to say that familiarity breeds contempt, then shouldn't all of us be fleeing from one another?
What, then, accounts for the fact that family love and loyalty frequently exists -- thrives, even -- despite the full awareness of foibles, sin, disobedience, disappointment? What keeps most families out of rampant discord and hostility? It isn't only families that defy the truism. Something exists that enables people to overcome interpersonal matters that would customarily produce ill will.
Along with increased awareness of the unlovely, in the family we also see more of the lovely. In the family we see the unattractive but also the attractive; sin but also righteousness; the fall but also redemption. It is a cause -- the cause of Christ that for believers demonstrates that God shows us his glory in part through the brokenness of men -- that causes us to revel in the good while not excusing the bad, that develops loyalty in the face of contempt.
For Christians, familiarity with our brothers and sisters frequently does lead to contempt. But real familiarity, familiarity that is more familial in the truest sense of the word, leads past contempt to godly love and loyalty. It is the grace of Christ that enables us to be familial in this sense -- to view those who are not necessarily under our roof as nevertheless somehow still in our charge.