Hey guys, I'm not LDS but I've had on and off interactions with members of the Mormon Church. As a Catholic, I find the Mormon interpretation of the afterlife much more reflective of a loving and forgiving God. My understanding is that everyone gets a second chance in the spirit world after death before their final judgement. However, I know that there is still a concept of Hell (which makes sense because Scripture talks about it quite a bit), but it's reserved for Satan, his followers, and "sons of perdition." My understanding is "sons of perdition" includes former Mormons who turn their back on the Mormon Church.
So, just to apply the whole Eternal Family concept in an example: John and Susy are faithful Mormons who are sealed in the Temple, and their three children are sealed to them. Child A goes on to be a faithful, temple worthy Mormon. Child B is a lukewarm Mormon who doesn't reject the Mormon Church but also doesn't follow all the teachings. Child C rejects the church and converts to another Christian denomination. They also have a family friend who is an atheist. Based on what I know about Mormon Doctrine, Child A would be exalted with her parents (she would need to marry to achieve full exaltation) at the resurrection, and before that, she would enjoy peace in the spirit world and maybe teach people in spirit prison. Child B and the atheist friend would go to spirit prison, and depending on the choices they make there, they would get to go to one of the three Kingdoms. But what about Child C, who is a Mormon apostate? Does he get a second chance in spirit prison, or does he go straight to Hell without hopes of redemption?
When I asked the missionaries, they didn't directly answer my question, and I couldn't seem to find a clear answer to this on lds.org. Links to additional information where answers to this question are spelled out (or just Scripture references within your answer) would be greatly appreciated. Thanks for helping me understand more.