What are the cons of taking out ROTH IRA contributions?

[Ludmila M.]

My husband and I were thinking of taking some money out of our ROTH IRA for the REI business. The amount we'd withdraw would be around 20% of our overall retirement funds. We are in our 40s, if that matters.

Aside from the risk of losing this money and inability to "return" the funds back to ROTH IRA in a lump sum, are there other serious disadvantages that we should be aware of?

I'll mention that my husband plans to continue his full-time job and making contributions to our retirement funds, and I will be the main person running the business. 

Thank you for your comments!

Best regards,

Ludmila