Personality and Friendship

Personalities... what sorts help people make friends and keep them? What aspects of mine should I alter, keep in check, magnify, or abolish to maximize the value and depth of beneficial Christian relationships?
I think I should change some things related to how I come across. I hope I won't end up identifying non-issues and changing things that will make me even less desirable to be around.

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Are deep friendships to be found primarily among those of very similar opinions, or can two people with somewhat different life styles be very close? It seems like friendships are of more value when the friends do not agree on everything and therefore can argue and learn from each other. (Keeping in mind, of course, that debates must be held in a loving and respectful manner.)