We read in Yonah 1 about the men who traveled on a boat with Yonah. When the sea ceased storming we read:
"And the men feared the Lord exceedingly, and they made sacrifices to the Lord and made vows." (Yonah 1:16)
Rashi explains that they promised to convert (Rashi on Yonah 1:16)
Question: Why did they convert instead of becoming righteous gentiles? If Torah does not require everyone to convert why did they?