Faith and Optimism
Optimism is knowing a good outcome is possible. Faith is knowing a good outcome is inevitable.
Jesus has the victory; which means we have it too. (1 Corinthians 15:57)
Now hear me out, I'm not saying that everything will look good on earth. Some things just don't go how we'd hoped. But that in no way means Jesus has lost.
Optimism can believe something good might happen. It's a little bit airy. It doesn't know how to deal with what looks like defeat. It's not a bad thing, it's a positive mindset.
Faith on the other hand is assurance of things not yet seen. Even if it looks bad - Jesus has the victory. Even if I'm waiting for heaven for this prayer to be answered - that's still a victory. It's a victorious life not just a positive mindset.