What Are Core Beliefs? (And How They Affect Low Self-Esteem)

If you’ve ever found yourself thinking “I’m not good enough” or “I feel like I’m the only one who can’t handle things,” you may already be noticing how certain beliefs shape how you see yourself.

In CBT, we call these core beliefs - the deeply held ideas we carry about who we are. They often sit quietly in the background but can have a powerful influence on how we feel, think, and respond to situations.

What Are Core Beliefs?

Core beliefs often sound like:

“I’m not good enough.”

“I always mess things up.”

“Good things never last for me.”

“Other people probably find me annoying.”

Often, we don’t consciously choose these beliefs - they tend to develop from experiences we’ve been through, or ways we’ve made sense of things over time.

When difficult experiences repeat - like being criticised, feeling left out, or worrying that you never quite measure up - it’s understandable that your mind might start drawing conclusions: “If this keeps happening, maybe it’s because of me.”

Why Do Core Beliefs Have So Much Impact?

Once a core belief takes hold, it often shapes how we interpret situations, even without us realising.

For example:

• A friend cancels plans ➔ “They don’t really want to see me.”

• You make a small mistake at work ➔ “I’m rubbish at my job.”

• Someone compliments you ➔ “They’re just being polite.”

Even positive situations can start to feel like evidence for what you already believe deep down.

How Core Beliefs Affect Self-Esteem

When these beliefs sit in the background, they can lead to patterns that keep self-esteem low, such as:

• Focusing on mistakes or flaws

• Downplaying achievements

• Avoiding situations where you fear failing or being judged

• Setting unrealistic standards to try and “prove” your worth

It’s not necessarily that the belief is true - it’s simply become so familiar that it feels like fact.

Can Core Beliefs Change?

Yes - and this is where CBT can help.

In therapy, we don’t force beliefs to change overnight. Instead, we work together to:

• Notice when these beliefs show up

• Explore where they may have come from

• Gently test whether they’re still true or helpful

• Build fairer, more balanced ways of seeing yourself

This isn’t about forcing positive thinking - it’s about learning to see the full picture with more kindness and perspective.

Final Thoughts

Core beliefs, if left unchallenged, can shape how you see yourself over time - often without you realising how much influence they’re having. And while these beliefs may have made sense at one point, they don’t have to define how you feel about yourself going forward.

With the right support, it’s possible to gently loosen their grip and build a stronger, kinder relationship with yourself.

If you’d like support in exploring your own core beliefs, CBT offers a safe and structured space to work through these patterns at your own pace. Feel free to get in touch if you'd like to find out more or see whether we might be a good fit to work together.