Constructed on the theory model of Theory-Research and Practice Relationship framework (Lesh, 2002), this study aimed to examine the challenges in instructional strategies in teaching interruptions, differentiated instruction, instructional emphasis as well as teaching resilience among 9 selected mathematics teachers at Paracale, National High School in Camarines Norte, Philippines, during first semester, academic year 2023- 2024. There are three distinct components of the study: First, it examined the lived experiences of ten mathematics teachers about the challenges they faced in post-pandemic time regarding teaching interruptions, differentiated instructions, and instructional emphasis. Second, it evaluated the teachers’ teaching resilience in the context of teacher behavior in the classroom and their self-efficacy beliefs. Lastly, the study focused on mathematical illustrations as one of the instructional strategies and its implications to mathematics education and instruction in particular and in teacher education in general. Both the challenges and resiliency have been incorporated in the discussions on their implication to teaching and learning respectively.