Some viruses have a lipid envelope around their protein capsid. The envelope can be dissolved with soap, but does that still leave the capsid and interior genetic material intact? If so, is the virus still active?
Enveloped RNA viruses will get inactivated quickly without a membrane. RNase is a ubiquitous enzyme that would quickly digest any exposed genetic material.
RNases are found in all cell types and organisms from prokaryotes to eukaryotes. These enzymes generally have very high specific activity, meaning tiny amounts of contamination in an RNA sample is sufficient to destroy the RNA. The major sources of RNase contamination in a typical laboratory include:
- Aqueous solutions, reagents used in experiments
- Environmental exposure, RNases are in the air, most surfaces and dust
- Human contact with hands and skin
Without a membrane (and any associated receptor-binding proteins), the genetic material of an enveloped virus would not normally have a way to get incorporated into and infect the host cell, in any case.
Your question is about enveloped viruses, specifically, but there is an interesting exception of a kind, so-called viroids that infect plant cells. These have no capsid or protein envelope, but are still infectious.