Living is not about a single lifetime. As you can already see, everyone dies and they will born again. It is called an existence or metempsychosis. What you're doing in this life not only matters to this lifetime of yours. They will come with you until you completely spend them to the very last. Just imagine if you buy a car with a two year leasing plan. You have to pay the monthly rental for two years. Otherwise you will lose the car. But karma doesn't work that way. If you do something bad or good, you have to spend the results of it no matter who you are or what you do.
Karma has two sides. If you do something good (intentionally), it will retain as good karma. If you do bad you will gain bad karma. They will pass on to your next life throughout your existence. But even there are two sides of karma they both lead us to the same thing. They both extends our existence and lead to forever continuity.
Think about our main goal which is achieving nirvana. In another words 'stopping the existence'. To do that you MUST do EVERYTHING YOU CAN to make your path ahead on the 'road to the truth' within this lifetime. You cannot predict your next life. You cannot plan it. Only thing you can do is making THIS life worthwhile.
Lets look at some practical things. If you look at your neighborhood you can see there are many successful families out there. You can see they get cars, houses and living expensive lives on their own. If you're a student you can see your colleagues getting graduated. If you're an employee you can see your work mates getting promoted. But have you ever thought about what will happen to their next life? What will they become? As I said earlier, even god cannot predict it.
Throughout your life you must do good things. If you don't you will have a hard time tomorrow. You can do your studies. You can work hard and be promoted. You can purchase expensive stuff. But always remember that you have to understand the truth about everything. Things you have purchased, things you have learned throughout your life will not come with you to your next life. Only karma will. You have to believe that everything is impermanent. When you understood you can eliminate desire, greed and lust. Then you will start to give. You will stop going after everything. And you will start realizing the need for discontinuing your existence. But before doing anything you must get rid of your ego and stop being conceited.
I personally do not have a permanent job, a girlfriend, a car or anything expensive which I can claim as mine. But why do I worry about it when I truly know that I will lose them all when I die? It is the ultimate truth. Even if you're the president you cannot change it.
Actually Lord Buddha's teachings are not religion oriented. You might be a Buddhist. You might be a Christian. You might be Islam, Hindu or an Atheist. But you all can benefit from the buddhist teachings. It is the core of every theory out there. That's why even science can't exceed it.
When you're realizing the truth about everything, you will be closer to nirvana. And you will shorten your journey throughout the existence. If you don't you will born again and again in different areas and different dimensions. And the worst case is you will never know what will you become tomorrow if you die today.
As a conclusion I'd like to say that if you read this to the end I think you've learned or at least remembered something. If you do please share this with your friends and network. I do not earn any revenue by writing this. But if you learnt something from this it's my pleasure.
"Nothing (you see, hear or feel) is real. Everything is impermanent."