There are at least two very major impacts that Henry VIII had on the church in England.
First, it was Henry who caused the break between the English church and the Roman Catholic Church. He caused this break largely because he wanted to divorce Catherine of Aragon and the Church would not let him (largely because the Pope was at that time being pressured heavily against it by Catherine's nephew, the Holy Roman Emperor).
Second, Henry was behind the dissolution of all the monasteries in England. Monasteries in those days were very rich and powerful. Henry dissolved them in part because they were Catholic and in part because he wanted their riches.
Thus, Henry had two major impacts on the church. He broke the English church away from Rome, making the Church of England and he dissolved all the monasteries in England, destroying what had once been the backbone of the Catholic Church in England.