As with the other existing rock acts in Britain, Richard's career was affected by the sudden advent of The Beatles and the Mersey sound in 1963 and 1964. However, his popularity was established enough to allow him to weather the storm and continue to have hits in the charts throughout the 1960s, albeit not at the level that he had enjoyed before. Nor did doors open to him in the U.S. market; he was not considered part of the British Invasion, despite four Hot 100 hits (including the top 25 "It's All In The Game") between August 1963 and August 1964, and the American public had little awareness of him.

Another important aspect of Richard's life was his conversion to Christianity in 1964. Standing up publicly as a Christian affected his career in several ways. He believed that he should quit rock 'n roll, feeling he could no longer be the rocker who had been called a "crude exhibitionist" and "too sexy for TV" and a threat to parents' daughters. However, his image had already become tamer due to his film roles and well-spoken manners on radio and TV. Richard intended at first to 'reform his ways' and become a teacher, but Christian friends advised him that he did not need to abandon his career just because he had become a Christian. Soon after, Cliff Richard re-emerged, performing with Christian groups and recording some Christian material. He still recorded secular songs with the Shadows, but he gave a lot of his time to Christian work, including his appearances with the Billy Graham crusades. As time progressed, Richard balanced his faith and work, which enabled him to remain one of the most popular singers in Britain as well as one of its best-known Christians. He was a leading figure in the Nationwide Festival of Light, protesting against the commercial exploitation of sex and violence in Britain, and advocating the teaching of Christ as the key to recovering moral stability in the nation.