What is the ruling on a Muslim's saying: "O Allah, do not admit me to Paradise if Jews and Christians enter it"?

If a friend supplicates against himself to be resurrected with the Jews and Christians, believing that it is impossible for them to enter Paradise, there is no harm in his supplication. A Muslim must guard his tongue and not supplicate evil upon himself. Also, dialogue with Christians regarding creed should be limited to those who are academically qualified.