Does “Sin no more, lest a worse thing come unto thee”... suggest the possibility of relapse?

Regarding Christ Jesus’ statement to the man he healed at the pool of Bethesda: after Jesus found him in the temple, “Sin no more, lest a worse thing come unto thee” ( John 5:14 ), does this suggest the possibility of relapse? So that even Jesus’ healing works needed further prayerful protection or understanding to cement the healing? And also, as a follow-up, what would be a “worse thing”? — A reader in Washington, US A:  At the Bethesda fountain, when Christ Jesus asked the man with the 38-year-old infirmity if he would like to be made whole, the man didn’t answer, “Oh yes, please, more than anything else. ” He offered an excuse as to why he was not able to be healed.