"Once bitten, twice shy" is an expression used to describe the phenomenon of going through a particular hardship that causes us to be reticent of moving forward! Ministry is such a thing where a bad experience can cause us to not want to engage in the future. The unbelieving Jews in Thessalonica persecuted Paul and Silas, but their love does not grow cold for the Jews, rather they "soldier on" as good servants of the Lord Jesus telling them that their Messiah has come!