Individual in-depth, semi-structured interviews with three mathematics teachers were conducted to investigate the dynamics of their life-long relationships with mathematics, synthesised as mathematical identity from different identity positions in the context of dialogical self. The qualitative data were scrutinised employing interpretive phenomenological analysis that displayed mostly positive instrumental relationships with mathematics and explicit connections between the teachers' life experiences and their distinct identity voices that surfaced in interviews. Similarly, teachers appeared to be experts in different professional spheres: pedagogy, subject or didactics. The teachers' accounts contain various models of relationships between the other-motive and the self-motive as reflected in their pedagogical approaches. Emergent patterns resulting from the interaction of the teachers' mathematical identity and their perception of students' mathematical philia/phobia included the humanistic approach with an instrumental interpretation of mathematics and its teaching methods, self-actualisation in achieving success in mathematics through hard work and the issue of attribution of failure in mathematics either to external or internal factors. Moreover, these dialogical models and interactive patterns show alignment with one of the core competences for educators in education for sustainable development, that is, achieving transformation in what it means to be an educator, in teaching and learning, as well as in the entire education system. Practical implementation of findings and limitations of the study are outlined along with venues for future research.