The person’s agentic “Will to Exist/Live and Survive” (WTELS) is overlooked in the literature. We proposed a measure as well as a conceptual predictive model for WTELS. The conceptual model included oppression and cumulative life adversities and WTELS as independent variables, existential annihilation anxieties (EAA), emotion regulation strategies, and self-esteem as mediating variables and psychopathology and posttraumatic growth (PTG) as outcome variables. The sample included 490 participants (age range: 14 to75, M = 26.03, SD = 10.90, 20.4% adolescents, 58.6% females) from three Egyptian cities that represented different regional cultures. Exploratory and confirmatory factor analyses tested the structural validity of the measure, Path analysis supplemented by PROCESS macro was used to test the predictive validity of the measure and the effect size for each mediator. Multigroup invariance analysis tested the invariance of the measurement and structural models. The developed measure was found to have good reliability, stability, and structural validity. Path analysis validated its predictive validity and indicated that WTELS had strong direct negative effects on EAA and the direct and indirect negative effects on psychopathology. Self-esteem and emotion regulation (reappraisal) were mediators of its indirect effects. WTELS had direct positive effects on PTG and direct and indirect positive effects on emotion regulation. WTELS had direct and indirect positive effects on self-esteem. Its indirect effects on self-esteem were mediated by reappraisal. The results indicated that both the measurement and the structural models of WTELS were strictly invariant across gender, regional, age, and religious groups. We further discussed the importance of developing WTELS-focused intervention and prevention programs.