Christians Jews and Muslims are realists. This means that they believe that whether you are a believer or not it makes no difference. You cannot make up your own truth, there is true and false. So being a believer makes no difference there is still only one form of worship whether you believe or not, and that is the one of their faith.
A Conservative Christian position would agree with this statement in the broader sense of Christianity. They would say the only legitimate form of worship would be the worship of God through Jesus Christ and any thing outside this would not be legitimate worship. This would exclude Islamic five daily prayers, Hindu Puju, Buddhist meditation and any thing else, which is not the worship of God through Jesus Christ, would be illegitimate. However within Christianity there is a vast range of different worship styles. Many conservative Christians would accept this wide range of different worship techniques.
The Roman Catholics would however broadly accept that there should only be one form of worship, the Mass. Until Vatican II and the vernacular mass, Roman Catholic Latin mass would be identical throughout the world and had been for hundreds of years. The Roman Catholics would broadly agree, as they believe that the only legitimate form of worship is that which takes place in the Catholic Church and that is mass and a few other forms of worship. The modern catholic wouldn't fully agree with this statement but they would be a long way in that direction.
Islam would also essentially agree with this as they have a set format of prayers and words in Arabic accompanied by set postures. In any mosque in the world this would be the same.
A more liberal Christian however would say that the way...