Rebirth does not relate just to past and future lifetimes. Every moment of our life we experience rebirth. Every day, we can begin anew through the thoughts we have. So even if we are still uncertain about "Rebirth," we can still see how it works within just one lifetime.
During Monday night's class, I read a short meditation to be done in the morning. Essentially, we pause before rising and consider how we want to spend our time that day: wisely or wastefully. We can consider the good things of the moment be they the sounds we hear in the early morning or the thoughts that arise. With positive thoughts thus reinforced, we will face the day in a better frame of mind.
By focusing our thoughts, we can positively direct them. By cheerfully greeting those we encounter as the day unfolds, we plant the seeds for happiness. We don't have to wait for these seeds to mature in some distant lifetime. When we smile, we feel better. Right away. Instant rebirth. Instant cause and effect.
One moment we didn't quite feel like smiling because we were wrapped up in replaying what happened yesterday or in worrying about what might happen tomorrow. But remembering that we had opted to be reborn that morning, we smile and our act of smiling manifests as happiness. And the happiness is shared as it is now felt by the one we smiled at.
Face each new day as a new beginning, a day in which to plant seeds and instantly receive some of the results.