Focus groups were used to analyse Christian lay public understanding of preimplantation genetic diagnosis (PGD), a relatively new biomedical practice. The paper explores how this often controversial genetic technology was contextualised and interpreted through the intersection of religious values and beliefs, secular and cultural knowledges, and lived experience and emotion. For the lay people in our study, PGD often created moral dilemmas that could not necessarily be resolved through Christian beliefs and teaching, but which required the expression of empathy and compassion. The findings emphasise the heterogeneity in individuals' interpretations of scientific issues and reinforce the need to consider public understanding of science and technology in terms of public concerns and meaning.