Knowledge and skills are the central themes of an education system. Nowadays, the main focus in on skills generally and on thinking skills specifically. The principle adapted currently is that education is not just transferring knowledge to learners or students but rather it is a process that is also directly related with the cognitive, emotional and artistic aspects. Cognition refers to reasoning and thinking skills in education. In this context, thinking skills and specifically critical thinking is to be considered in curriculum development process. The critical thinking helps the learners to express their opinions on the scientific or social issues, making decisions, constructing plans and solving their problems. This study aims to determine the impact of utilizing critical thinking skills in education. In fact, educators believe that critical thinking is important because criticism leads to creativity, criticism and creativity. The results of this process will help problem solving, innovation and development. But the challenge here is how learners can have the required critical thinking skills. The role of the teacher in developing the skills of critical thinking is another challenge. The data for this qualitative research was collected with the help of face to face interview, focus group discussion with participation of 8 teachers of Science and Religion for the intermediate stage in Palestine during 2018-2019. The data were analyzed and the findings were given under subtitles.