This study aims to analyze the impact of character education implementation by teachers in Sunday school on the aspect of spiritual intelligence in children at GPI Sidang Wismar Saragih church. The research problem formulation is how the influence of character education implementation by Sunday school teachers on the development of children's spiritual intelligence at GPI Sidang Wismar Saragih church. This study uses a quantitative method by analyzing the influence between the variables under investigation. The research population consists of 35 children participating in Sunday school activities at GPI Sidang Wismar Saragih church. For data collection, the researcher used a closed questionnaire with 27 questions for each research variable, using a Likert scale with 5 response options: strongly agree, agree, neutral, disagree, strongly disagree. Thus, it can be concluded that the implementation of character education by Sunday school teachers (X) has a positive influence on behavior (Y) in the population under study. Furthermore, the influence of Christian Religious Education teachers (X) on the development of spiritual intelligence in children at GPI Sidang Wismar Saragih church (Y) can be explained through a linear equation model Y ̂= 50.3 + 0.518X.