I can only agree to ryecoaaron.
Raid is not a backup. It is a redundancy system to prevent dataloss if a disk fails. It does not provide any protection against file deletion, mistakes in any form, or other malware (including encryption or wiping).
So you should always have a backup, and you may want to have a RAID array to prevent downtimes for your application. But if you have RAID it is both, backup AND raid.
If you do not need any backup, then not a problem - go with raid.
