It's basic maths, really. The less we consume, the more we're able to give. The reality is that at present the average Australian is consuming more than our fair share. If everyone in the world consumed as much as we do on average, we'd need almost four earths to sustain that kind of living. That doesn't mean that we need to live impoverished lives, it just means that we need to set limits on our consumption. Bob Goudzwould wrote that 'a society that doesn't have an understanding of what 'enough' is, will never know abundance because abundance means having more than enough.' When we haven't worked out what 'enough' is, luxuries quickly become expected norms and they lose their shine as we search for the next bigger, better thing.
Attempting to live simply turns things we have learnt to expect, back into luxuries that we savour and take the time to enjoy. It also reduces our environmental burden and frees up resources for others - helping us to live in the space that Kate Raworth calls the 'doughnut' - the beautiful space between the earth's environmental limits and our human needs. There's a bunch of ways you can live more simply, and we'd encourage you to have a read of Richard Foster's Freedom of simplicity. Its packed full of great insights and ideas.