All have sinned and fall short of the glory of God.
That is an incredibly optimistic statement.
The sophomoric reading is that you are a bad person who should feel bad. There is little optimism there. To better appreciate what this statement can do for you, consider it in light of another Biblical statement,
Have I not said ye are Gods?
You fall short of your own potential. In other words, “All have sinned” is an acknowledgement of the simple fact that you are not who you want to be and who you are capable of being. The optimism is the possibility nested in this statement; that improvement toward your divine potential is possible.
It needn’t be read religiously if that distracts you. Your own divinity can mean simply your ideal version of yourself; the best you can imagine being and desire to become.
If you have godlike potential and want to move toward the ideal form of the person you want to be, you must begin by acknowledging you are not there. Progress requires discontentment with your current condition. Then you can move to the optimism that says, “Which is precisely why I am constantly taking action to move towards what I am not yet.” To see the possibility of your future potential requires accepting your current distance from it.
In Christian language, this is the process of salvation. You could call it self-improvement, enlightenment, or progress if you like.
The first instinct is to think “Ye are Gods” is the optimistic statement, but it’s not.
It forces you to confront the reality of your own lack of divinity. The fact that you can imagine a self better than who you currently are reveals inescapably that you are not yet Godlike. “Ye are Gods” by itself can cause cynicism or depression: either the statement is a delusional sham because I can see I’m not Godlike, or I’m a sham for my failure to be so.
Hope is found in first owning the fact that you fall short of your potential and desire. This leads to the discontentment necessary to drive action and the optimism that action can move you closer.