Probability
Example: This might work. So it's worth giving it a go.
Most people are naturally optimistic, believing good things will happen beyond what chance dictates. While of course you can be over-optimistic, it is better to be hopeful and believe that good things will happen than to be depressively pessimistic. Evolution has made us this way because getting out there and trying gives an infinitely better chance of succeeding and growing than not trying at all.
When you are optimistic you have a more cheerful disposition, which influences others to like you and help you more. Optimistic people are more resilient and will pick themselves up, dust themselves down and get on with things -- without any permanent loss in optimism.
Ability
Example: I can get there. I just need to keep going.
A common limiting belief is 'I cannot...'. When you believe you are not able then you will be unlikely to try. And even if you do, the limiting belief of inability will undermine you and may well precipitate failure. Even if you succeed, there is a tendency to sustain the limiting belief by attributing the success to luck.
Better is to believe you can do pretty much anything, to have confidence in your own ability to succeed. If you believe you can, then you have a far better chance of getting there.
Having said this, it would be arrogant to believe you could just pick up an instrument and play like a virtuoso, so 'can do' beliefs must be moderated to allow for practice, failure and learning. If you believe 'I can play this well if I keep practicing' then you will likely succeed. Belief in your own resilience and ability to learn are consequently very powerful enabling beliefs.
Existence
Example: I'm intelligent. If I work hard, I can learn most things.
A variant on the limiting belief 'I cannot...' is 'I am not...' ( or maybe 'I am' someone who does not). Framing yourself as a person who does not do certain things is a great excuse for inaction.
The reversal of this is to create enabling beliefs that say 'I am' something that will help you, such as 'I am friendly' or 'I am determined'. Our sense of identity is hugely important to us and 'I am' statements directly reflect our constructed self. This can make existence beliefs hard to change, but it also makes them very powerful.
How we believe drives our actions, often rather more than natural truths. Indeed, in many of our decisions we have limited information and have to rely on belief, even if it is weak, to guide our choices. What and how we believe consequently has a huge impact on what we do and whether we succeed.
Enabling beliefs are...
Many of us have limiting beliefs which hold us back in life. Yet we can also have enabling beliefs that help us forward. Enabling beliefs are not foolish beliefs. If I believed I could fly, then I probably would not last long. Enabling beliefs lead to growth, success and happiness.
Just as limiting beliefs are often avoidance in disguise, enabling beliefs may well lead to people taking risks, which may sometimes lead to failure. Yet enabling beliefs must also get you through failure, recovering, learning and carrying on. It is only through risk that we make progress.