Roman Catholic Church
The Catholic Church's position on therapeutic cloning follows from its belief that the embryo is a human being. As such, you are sacrificing one person to save others. Imagine a doctor came into your home and knocked you out - then took you to a hospital and took out all your organs to put into other people. When your horrified parents complained, he would say that he had killed you but saved the lives of five other people. It wouldn't matter how many people he'd saved - you don't kill an innocent person even to help several others who are dying. This is basically what the Catholic Church are saying in 'Dignitas Personae' (2008):
To create embryos with the intention of destroying them, even with the intention of helping the sick, is completely incompatible with human dignity, because it makes the existence of a human being at the embryonic stage nothing more than a means to be used and destroyed. It is gravely immoral to sacrifice a human life for therapeutic ends.
They go on to say that you can get stem cells from other sources, and that it's okay to do this if you don't harm the source of the stem cells:
Methods which do not cause serious harm to the subject from whom the stem cells are taken are to be considered licit. [licit means allowed or legal]
Church of England
The Church of England wants to support efforts to find treatments for serious conditions. At the same time they are cautious about using embryos to do this. As is often the case with the Anglican Church, they do not give a definitive statement, but support the use of embryonic stem cells if it is 'absolutely necessary' and 'once all other avenues have been explored'/ In 2008, the Church wrote the EMBRYONIC STEM CELL RESEARCH INVESTMENT FRAMEWORK:
The Ethical Investment Advisory Group attaches importance to the significant potential of human embryonic stem cell research in the development of new knowledge, life changing treatments and possible cures for many debilitating diseases and injuries, including Parkinson's disease, diabetes, heart disease, multiple sclerosis, burns and spinal cord injuries. However, in harvesting embryonic stem cells for research, the Group remains cognisant of the sensitive ethical issues surrounding this research. In particular, the status of the embryo and whether it has the same right to protection that is accorded to early human life, on the basis of the traditional respect for the sanctity of that life.
...the Group recognises that there are different, but principled and sincerely held views among Christians on the morality of embryo research
