Hello and welcome.
Consider this analogy. I know it's somewhat flawed, but most analogies are. What is France? Well you have the idea in your mind of what it is. But let's break it down. Is France characterised by its borders? No, they have changed many times. Is it characterised by its language? No, more countries speak it and it's changing; slowly, but it's changing. Is it characterised by its political regime? No. It was a monarchy, then a republic, then an empire, then a republic again. Is it characterised by its cultural values? No. We all know these change with time and are not even necessarily coherent. So what the hell is France? Because of the above, no matter what angle we aproach France, we realise it's a convention. On the ultimate level, this convention doesn't exist per se. But France is, at the moment, on the map, the french speak french, they are a republic, and they have a series of cultural values that are present in France.
Emptiness seems complicated but I think it's this simple: we see things as conventions and these do not exist. It's not the things that do not exist. It's the conventions. Why is it sooooo important, then? Well, do you think that, if the french and/or their neighbouring countries, really knew, in their heart and bones, that France (and their countries) is just a convention; do you think there would be wars between them? It would be awfully ridiculous fighting a war because of a convention. It would be ridiculous for a soldier to think of giving his life for a convention. Or to kill another person just because their convention is different. Yet millions have died because they didn't understand this. There was war, famine, disease and poverty. Just this seemingly-tiny shift in aproach would solve nationalistic wars automatically.
This is what happens with us. The "you" that you know is a convention. That doesn't mean that you don't exist. It just means that you are different from what you think you are. And that makes all the difference. If you knew this in your bones, it probably wouldn't occur to you to care so much if someone called you a good or a bad name. It wouldn't occur to you to live a life for the sole purpose of the satisfaction and protection of a convention that doesn't even mathc reality. That must be liberating.
On to the second point: there is a difference between not being atached and not caring. This is also very, very important, imo. For example, Dipa Ma, who declared she was a once returner (and was stopped by her teacher in order for her not to say more; we can infer, without much abuse, that she had more to say about that and, therefore, that she was at leat a non returner). She said that once she was liberated from this ignorance, she really enjoyed her life better. It's not that once you don't have atachment you become neutral. I interpret her testimony as saying that if you have wisdom you can really enjoy life, because you know it will end. Therefore you enjoy all the things that will end while you can, and don't suffer when they end.
Now, an "illusion cannot liberate itself". Correct. A convention is a convention. It cannot do anything to change itself. The flux that clings to this convention can let it go and see it for what it is: a convention.
Why work hard for this? That's a good question. Compared to the Buddha's time, we are like devas, in terms of quality of life. So it's somewhat natural that we don't see the need to work hard for this buddhist goal. There are two answers for this: 1- Although sensual pleasures are good, spiritual pleasures are even better. So if you're an hedonist, you better get into the real stuff
. 2- Will you be prepared if someone tells you that you have cancer and have two years to live? Are you prepared for the death of any of your deeply loved ones? Or are you prepared to have a terrible accident and be bound to a wheelchair? It all seems completely bearable for now. But we never know what the future holds. Maning up will probably not be enough if the future events are terrible enough.
Even if you think "why all this trouble for that supposed happiness? is that happiness even real?", ask yourself "Is my present happiness real?" The answer I found so far is that my mundane happiness is kind of a lie. If spiritual happiness is also a lie, well, it's a better lie. It's not the case that mundane happiness is not a lie. So if I ad to chose between lies, I would chose the one that maskes me happier. But, anyway, people who have experienced the more advanced stages of the path report a clear sense of reality. That what they are experiencing is concrete and real. Only one way of finding out.
Morality is, in my opinion, very different in buddhism than in christianity. Morality is not about sacrifice. It's about doing what is useful to your deeper happiness. It happens that what is useful to your deeper happiness, is also useful for others' happiness. So if you want to be a really commited selfish and hedonist, the best way to do it is by being generous and loving.
And to the final question, for which I have no clear idea of how to answer: if there is no rebirth, what is the point? I won't remember anything, so why care so much? The only two things that occur to me as sensible are that even though sensual pleasures are good, spiritual ones are better. And we only know that humans (and probably animals) don't remember their past lives. What about devas or hungry ghosts? Can you guarantee that, if you're reborn as a deva, you will not remember a few lives behind, including hell? Are you willing to risk being reborn in hell and remembering and "being" your self, but sort of older?
Anyway, enough with my drivel. Maybe it's of use for you. It has been to me.
And the Blessed One addressed the bhikkhus, saying: "Behold now, bhikkhus, I exhort you: All compounded things are subject to vanish. Strive with earnestness!"