....from hypnotherapy (mind-washed) / drug-induced. To get people to believe in God these days, let a lone martyr themselves for God doesn't hold statistically. From a cultural and religious viewpoint, such spiritual gifts are inherited. Like a royal bloodline and not conventionally endowed on some random Joe. Historically, martyrs were murdered, they didn't go into the battlefield alone to be killed or kill themselves. Suicide is an honor code written in some cultures for penance. Like to absolve a guilty conscience. It's not justified by religion or God.
The likelihood of an extremist being an outlier are much more unlikely than a cohort subject to an intervention. For instance, the likelihood of a suicide bomber having priors, a network and a support system, under some warfare program is more likely than some random outlier coming out of nowhere because God told them it's a good idea. If indeed they truly thought it was God, God has His interventions.