Do you mean he has no savings apart from the Bitcoin? If yes, then it is the wrong approach to investing in Bitcoin. On every passing day, we humans always have one need or another, and it is very important to keep some fiat money so that one can use it to settle our needs, should any arise. Just advise him not to lose faith in wanting to invest in Bitcoin again, but rather teach him all the security measures you have learned so far on how to safely protect your Bitcoin and also how to protect yourself against some scammers. The worst thing that could happen is for him to repeat the mistake of being scammed a second time. Also, when investing in Bitcoin, he should save some fiat in case of needs and emergencies, and then he can invest the rest that he wishes to invest in Bitcoin.