The Church of England has been accused of "dumbing down" the baptism service, one of the cornerstones of the faith, by changing its wording so parents and godparents no longer have to "repent sins" and " reject the devil".
A trial of the new wording, aimed at making it easier to understand, will last in parishes until Easter.
Former Bishop of Rochester Michael Nazir-Ali, writing in The Mail on Sunday, branded it as part of the "constant dumbing down of Christian teaching" rather than making an effort to explain the meaning of baptism.
In the original version, the vicar asks: "Do you reject the devil and all rebellion against God?", prompting the reply: "I reject them." They then ask: "Do you repent of the sins that separate us from God and neighbour?" with the answer: "I repent of them."
No mention of the devil or sin is made in the new version in which parents and godparents are asked to "reject evil, and all its many forms, and all its empty promises".
"Instead of explaining what baptism means and what the various parts of the service signify, its solution is to do away with key elements of the service altogether!" Dr Nazir-Ali says in the article.
" Rather than the constant 'dumbing down' of Christian teaching, whether for baptism, marriage or death, we should be spending time preparing people for these great rites of passage.
"When it comes to the service itself, the need is not to eliminate crucial areas of teaching but to explain them.
"It is best to call a halt to this perhaps well-meant effort before it further reduces the fullness of the Church's faith to easily- swallowed soundbites."
A Church of England spokesman said the alternative materials are being piloted until the end of April.
The baptism service currently used by the Church of England has been in use since Easter 1998, but the wording was amended by General Synod in 2000 and again in 2005.
The new version is seen as a possible alternative to the wording in the Common Worship prayer book which will remain in use.
The spokesman added: "In 2011 a group of clergy from the Diocese of Liverpool brought forward a motion to the General Synod of the Church of England requesting materials to supplement the baptism service 'in culturally appropriate and accessible language.
"Specifically the motion requested new additional materials which would not replace or revise the current baptsim service but would be available for use as alternatives to three parts of the service.
"The Liverpool motion was passed by General Synod and as a consequence the liturgical commission has brought forward some additional materials for discussion by the General Synod at a future date where they will be subject to final approval by the Synod.
"At its last meeting the House of Bishops agreed that the additional materials should be piloted and they were sent to over 400 for a trial period which lasts until the end of April.
"The texts have no formal status without approval by General Synod."