Jealousy can be tough. A lot of people can never overcome it. Jesus family did, though. Earlier in Jesus ministry they tried to come to get him and take him home because they thought he was crazy, or lying, or something. But now they must have realized that He was who He said He was. It's just tough to take sometimes because we knew them growing up. We know all about them. They seem more human to us than anybody else because we know them. So when they start doing great stuff, we have more trouble accepting it.
Taking that even further, the closer we are to somebody the easier it is to not fully appreciate them. If someone I work with everyday accomplishes amazing things, I get used to it and forget just how amazing it is. What if we continually thanked and appreciated people for the things they do everyday from the mundane to the remarkable? I bet people could accomplish more with all of that encouragement. Just a thought. JM