Spiritual posts delivered via WhatsApp were found effective for mothers of children with ASD in mitigating parenting stress and building parental self-efficacy, confidence and resilience as compared to a control group. Intervention compliance was a prerequisite, and, middle-class mothers, highly qualified, salaried/self-employed, who perceived full support from their spouses/families and who also participated in other support groups or skill development programs benefitted most. Latent class analyses revealed six subgroups of participants likely to gain most from the intervention: middle class mothers, highly qualified, salaried/self-employed, who participated in other skill development programs, above threshold posts readers and homework doers. Spirituality built mothers' psychological resources, but dyadic interventions may be needed for dealing with challenges and uncertainties of autistic child's emotional/behavioral characteristics.