This may seem like a silly question, but it's the source of a years-long family feud, and I'd really like to know the answer. Sorry, it's a little long.
My brother was made an elder when he was 18. He never received his temple endowment, but remained active while he was struggling with whether or not he could serve a mission in spite of some mental health issues. He decided to stay home, but held several callings, including home teacher, primary teacher, and working with the scouts. Then he fell in love with a non-member. He moved in with her. They had a child together. He was put on probation by his bishop. He stopped going to church. After five years, he and his girlfriend finally got married. When his son was 7, mom started asking him about letting her grandchild be baptized. He thought about it, started going to church again, let our dad baptize his son. The new bishop felt that my brother had fixed his mistake. Once he'd been active for a certain amount of time, the bishop told him he was once again a member in good standing, and could take the sacrament. He happily substituted in the nursery (weird, right?). He was waiting for his wife to be baptized so they could get their temple endowments together.
Then, my youngest brother was blessing his son in church. They asked all our family's elders to come up. My brother joined in the circle to give my nephew a name and a blessing. I didn't think a thing of it, but after Sacrament meeting, my father was very unhappy. Still in the church foyer, he berated my brother, quietly, for half an hour for joining in the circle when he wasn't worthy. My brother took the tongue-lashing, went home, and never went to church again. It's been 13 years.
I know it won't change anything, but I need to know who's right. My brother was an elder. He wasn't giving the blessing. He'd stood in the circle years before as a new elder when we'd blessed my oldest son. So is there a requirement to have a temple endowment before participating in this type of ordinance? Does your priesthood authority expire if you don't get your endowment within a certain amount of time? Can you be an elder who exercises his priesthood authority without going to the temple? My dad was ward clerk at the time. Might he have known something I don't know?
Thanks for your help and thoughtful consideration. You have no idea how much an answer would mean to me. My brother is my best friend and it kills me to see him so resentful towards the church.