The Sunday Times newspaper said the phrase is on a banned list of abusive and offensive terms that cannot be used for messages.
It emerged when a pastor's wife was blocked from leaving a message on a bouquet of flowers because she wanted to say "with love from Christ Church Teddington".
When the woman called the retailer's customer service line she was told the word could have been blocked.
The call centre was able to enter the message for her.
The message facility had disappeared from the website although a spokesman for M&S told Premier this was not related to this issue and it was now working again.
Premier has found terms like Allah, Mohammad, Buddha and jihad were allowed.
A spokesman for Marks and Spencer said: "An automatic phrase checker is in place to prevent the use and misuse of certain words and it includes hundreds of words of varying nature. The words Jesus and Christ are included to prevent their misuse."