I want to start a business but I'm afraid that if I fail I will be unable to pay. What can i do?

Take angel loans. These are loans from family and friends who wouldn't be too hard on you should you stumble. Also try to be optimistic and not think too much about failure. You cannot succeed if you don't try.

This is a genuine concern, especially if you are leveraging your assets for this idea; for example, using your house as collateral — bad move.

I’m personally against taking out loans to start a startup; unless the loans are out of your 401K or similar. Maybe once the startup is going, and has a proven revenue stream, you can take out bank loans or get investors to improve your operation.
Well, There is also an excellent solution for a significant amount of debt. Debt free company can help you to pay your debt without any pressure. So, all I want to say you can grow your business.

As long as your business idea deals with something you truly are interested in and you have some sort of increased knowledge with the subject then you should not have much to worry about. If that is not the case then your business could be an extremely risky investment. OutsourceYourAccounting offers accounting consulting that could give you better outlook as far as your potential financial status before getting too far along with your business venture.