Happiness is a journey. We need to make the correct and relevant changes in our lives. Forgive the past. It's happened, it's unchangeable, but don't forget the lessons you've learned; let go of all regret. The future hasn't happened yet. It's important to dream, but don't stress, it's changeable. Focus on just these 24 hours. Take each day as it comes and forget the things we can't change, change the things we need to change, pray for the wisdom to tell the difference between the two.
Not the worst user submitted quote, but the last sentence very likely is you paraphrasing a well known quote. Also, I am going to edit the sentence "Focus on just these 24 of hours." The stretch from Forgive the past... to ...let go of all regret. also needs some work, but it's not as simple to fix.