"...I am concerned about how our future generations yours and mine will cope with the growing pressures on our religious heritage not least from the sharp increase in the Muslim community, Should we then continue to trample down the only real resisstance we have to being absorbed into Islam or any other religion..."
Our religious heritage in the European continent consisted of multiple wars and witch-hunts (Inquisition). The Abrahamic religions, Judaism, Christianity and Islam are all authoritarian religions which not only believe that their religion is the truth but condemn those who are not part of them to either genocide or a make believe inferno where everyone is tortured for all eternity.
Then, in the United States we had the Puritans who executed those who were not of their religion. This included the famous Mary Dwyer who was hung from a tree by the Puritans for the high crime of being a Quaker. Such intolerance is built into the Bible both Old and New Testament.
This Biblical attitude and the religions based on it does not make for a worthy "heritage".
As for Islam, it is as incapable of converting large numbers of Christians as Christians are incapable of converting mass number of Muslims. There is an issue in Europe because of the large numbers of alienated and unemployed Muslim youths who are ripe for conversion to tyrannical versions of Islam but that can be handled by stopping immigration from those nations.