"Does the Church accept that guardian angels exist and are those angels seen as good or bad for the individual?"
The Church of England officially accepts the teaching of the Bible and therefore the question ought to be, what does the Bible teach on this matter? However, regrettably, there are many members of the Church of England, including clergy, who do not accept the teaching of the Bible.
The idea of guardian angels is not in its origin Christian. It appears to have been held by many different cultures. For example, the Greek Socrates, before the first coming of Christ, claimed to have a demon as a counsellor, and it is commonly thought that this refers to the same concept. The name often used being "attendant genius".
The fundamental concept of a guardian angel is that a person has a particular angel who watches over them.
The Bible does not itself teach this one-to-one correspondence, but it certainly does teach a lot about angels and that they watch over the elect. Angels are mentioned many times in the Bible, something like 200 verses in total although very little detail is given.
There are two verses in Scripture that are sometimes seen as teaching about guardian angels:
In Hebrews chapter 11 verse 14 the writer says:
Are they not all ministering spirits sent forth to minister for those who will inherit salvation?
This certainly means that part of the task of angels is to attend to Christians. In itself however this verse does not amount to a one-to-one task, which is what is implied by the idea of a guardian angel.
The other reference is something the Lord Jesus Christ said whilst talking about children:
See that you do not despise one of these little ones. For I tell you that in heaven their angels always see the face of my Father who is in heaven.
This certainly could refer to the idea of guardian angels, although it might simply suggest that angels have a particular role in watching over children. Whether this means all children, or just those who will ‘inherit salvation’ is not clear.
It is wisest to say that the idea of guardian angels is not explicitly taught in Scripture. Therefore it is unwise to dwell too much on the idea since inevitably this will mean drawing conclusions which Scripture does not teach.
Nevertheless Christians may take comfort from the fact that part of the task of angels in general is to minister to those who will inherit salvation.
Angels - page to follow