One can benefit from mindfulness practice without believing that suffering is the main fact of life, desire is undesirable because it is the source of suffering, or that modern life is teaming with toxic elements. You don’t have to believe in the categorical discontinuity between being “awake” or “enlightened” and the normal state of consciousness, nor do you need to elevate the Buddha and other masters to a status beyond the merely human. You don’t need to believe that there’s a special state called “awareness” that the vast majority of humanity does not inhabit and which is different than executive attention, existing in parallel with other neurocognitive processes.