First, identify what your views/morals/principles are.

Then, critically analyze them and find the leaks. Dig into where you're weak or unsure and evaluate or change your stance until it is airtight.

Any time you receive new information, repeat.

This way, you'll be prepared to defend your convictions when the time comes.

Or

Try to break into your own house, make it more secure and repeat until you can't find any more ways to do so.