If a proposal promises $$BIG in savings but postpones serious cuts to some other year, that proposal is a lie.The 20th C was in general the period where we accepted the idea of people currently living paying an enormous cost for the sake of those who come after. Not only the utopian schemes of communist, national socialists, and their watered-down cousins, but neoconservative hopes of peace in the Middle East, and the whole idea of deficit spending reflects this. We used to sell education at town meeting with the idea that those were of school age now needed it. Now it is a federal idea, and we "invest" in education for the economic benefit of those who will come after. Environmentalism is now suffused with the idea. It was originally marketed as a way to clean things up for our own use now. As James noted, it doesn't seem to work that well. I wonder if people with fewer or no children fall for this line of reasoning more easily.
Not that it never works. There have certainly been infrastructure investments that have paid off a hundredfold. However, we have a skewed view of these, as we are seeing them only in retrospect, no longer aware of the grand plans that didn't work and slipped beneath the waves. It's one of those ideas that works well enough to persist, even though it may be an overall loss. It certainly seems to be a net loss, with neither the present nor the future generation benefiting.
When it's borrowed money, it's not our sacrifice at all, and it is deeply dishonest for politicians to say so. It is money borrowed from the future to be spent on the present.
Christianity, and most cultures, give some thought to posterity, but not like this. The focus on actual people, rather than hypothetical ones, is much stronger before the 20th C.