The purpose of this study was to explore the effectiveness of professional development programs in Christian schools. This study compared the perceptions of Christian school and public schoolteachers towards their professional development to determine if any statistically significant differences existed among Learning Forward's 12 standards of effective staff development. Learning Forward's Standards Assessment Inventory (SAI) was utilized as the assessment instrument, and participants' perceptions were measured regarding their schools' professional development programs. A total of 655 teachers participated in this study, which included 305 Christian schoolteachers and 350 public schoolteachers. This quantitative study utilized a non-experimental, comparative research design. For this cross-sectional study, two research questions and two main hypotheses provided the framework for exploring teachers' perceptions regarding their professional development experiences. First, the researcher compared the composite mean scores of the 12 professional development standards between Christian schools and public schools by using an independent-samples t test. There was no statistically significant difference between the composite mean scores between Christian and public schools. Next, the researcher compared each of the individual 12 standards using a MANOVA. Subsequently, to verify these results, 12 individual independent-samples t tests were performed. There were statistically significant differences among the 12 standards. Christian schools scored significantly higher than public schools in the equity, leadership, family involvement, and resources standards. Public schools scored significantly higher in the data-driven standard.