Rebbe Nachman teaches (through his principal pupil Rabi Natan) that we should serve HaShem anew every day, as if the world was created today and today is all we have.
The Arizal teaches (through his primary student Rav Hayyim Vital) that there are myriad connections between all of creation, that within any part of creation you may find aspects of every other part.
Taken together, if we want to achieve the pinacle of our avodat HaShem every single day it means each day we must start from the beginning and work our way all the way through to the end.
Yeah, I know that doesn't sound like much of a hidush, but it has a lot of interesting implications.
If all we have is today, and yet we are given a world rife with all manner of spiritual levels and perceptions, then they have to be accessible to us today.
Each day we can live through the 3 regalim, sukkoth, pesach, shavuoth. We get to experience Shabbath. We get to receive the Torah, we get to leave Egypt, free from bondage. Every day we can be forgiven for all our failings and wipe the slate clean. Every day we can start as a novice and become a talmid chacham, a tzaddik, a navi. Every day Rua'h HaKodesh is available to us.
This isn't to say that nothing takes time to accomplish, but it does mean that you can taste every spiritual level every day. We can earn a nefesh, ruah, neshamah, chayah, yechidah each day. Anything you've ever learned about or heard about is attainable, within your grasp, today.
It's not a simple concept it's a really involved one, so I'll try and explain the little bit I can understand: Everything is interconnected. This means that while I might be holding on a very low spiritual level, the level that I'm on is comprised of many different levels, the highest of those share something of the nature of the highest spiritual levels that exist. This means there is a spiritual level attainable today that is akin to 'prophecy' on the level at which you are holding.
Think about, for those who worry about yesterday, think about how much is available to you today, regardless of yesterday. For those of you who hope to attain something some day? Why wait when it's all available to you today? Better yet, if you think it's a one-time thing you will accomplish sometime in your life, know that when you get there, you will realize, wow, there's still so far to go, why not start now? See how far you can get today; not this week, not this year, today. That's a small enough amount of time to work in order to see results.
It's not a trick, it's a reality. But know that to get there you have to pursue with sincerity, with discipline and with all your heart. It's exactly as the talmud promises: "When someone tells you they tried and didn't achieve, don't believe them." God doesn't gain pleasure from seeing you fail. You are the only one comforted by your failure, if you are looking for excuses to give up trying.
What have you got to lose? 24 hours? How much can you attain in that time, you and I both wouldn't believe it? Rabi cried on several occasions, "There are those who earn their [place in the] world [to come] in an hour."