To answer this question we have to go back into the time where there was no matter and time or anything at all, yes I am talking about the time before the big bang(Technically there was no time(nullandvoid) before big bang but just for the sake of answer I am saying). I expect that you already know about the big bang theory. So according to the Big Bang theory we all come after and from the big bang, isn't it true?
well I guess nobody will look with this perspective that in reality we all are interconnected the question arises how? as I mentioned earlier that since we all come from the same energy group, the energy which was released at the time of Big Bang and matter was formed there after, which is the source of this whole creation, we all including solar system, matter, antimatter and all all are the consequence of Big Bang.
So energywise or matterwise we all are same and are interconnected. No logical theory can deny this argumental fact because this logic can only be failed when we assume that bigbang was not the reality.
And if we talk with respect to the religion or mythological aspect then, they are also saying the same thing i.e.. physically we all came from the very energy release at the time of Big Bang so we all are same or brother or like a family we all are child of the almighty energy or God whatever you say it.
I hope you like this argument. :)