Help the younger to learn
Ask yourself this. What do you care about? Life is a struggle maintained by the living. I could not eat meat, but technically a plants living also. That isn't to say I should treat the animals poorly. Even plants grow best in maintained appropriate conditions. There are things that throughout time we could learn. Today with this internet, it's spread across our globe at near instant speeds. There are some things that have to be learned over time, however. When a baby is born, it's not like it truly understands what reality is. It's a learning process for all of us.
We see there is more to existence, and why not exist there, if we're able? I think we're going to have to come to greater understanding of gravity and the physics behind it before we stand a chance long-term. Maybe over the span of a few civilizations lifetimes, we could achieve planet conversion. If gravity is just an energy well anyways, we may as well use some of it. Harness it as best we can.
If the future didn't exist, it wouldn't matter how you treat things. Individual lives are incredibly short lived if what we know about reality is true. I've never lived forever, nor to I plan to spend much effort in finding a way how to. My influence is now and forever, so long as you can read this. Maybe it doesn't make you do anything in particular, but like crushing a being from the past, it'll reshape the future. You can chose to do many things, you have as many options as you like, as you are a being of infinite capability. Any individual among you can chose to do as they please with any of the thoughts they think next. I'd argue it's better to think more sound and wholesome thoughts as they're the kind that unite societies. People want to protect themselves and the things they care about. Help people, and you become one of the things they care about. (Usually)
I'll leave you with The Beatles. Enjoy.