Why 40 Can Feel Like the Age of Ripening for the Soul

There is something about turning 40 that unsettles people, but not always in a bad way.

For some, it feels like loss. The loss of youth, the loss of illusion, the loss of time one imagined was endless. But for others—and I would say for many of us who care about the life of the soul—it can feel like the beginning of a truer life. Not easier. Not shinier. But truer. By 40, many people are no longer asking, “What can I become?” so much as “What is worth becoming?” That is a deeply spiritual question, and it is one of the reasons this age has long carried a certain sacred weight.

Now, if we are going to speak honestly, research does not say that 40 is the exact age when a human being suddenly becomes “fully mature” or officially qualifies to be a mystic. The soul does not work by birthday. Grace does not wait for a calendar. The scientific evidence is more modest and more beautiful than that. What it suggests is that by around 40, many people arrive at a kind of integration. They are no longer simply developing in the raw sense of becoming adults. They are often becoming more inwardly gathered, more tested, more realistic, and sometimes more open to mystery.

Neuroscience helps a little here. The popular idea that the brain “finishes” in the mid-20s is only partly the story. Yes, the systems involved in judgment, self-control, and executive function mature much earlier than 40. So we should not say 40 is the first moment of adulthood. But the brain continues changing beyond that. Some research notes that white matter volume peaks around age 40, and that adult development involves stronger long-range connections across the brain. In plain language, this may support a more integrated way of holding thought, emotion, memory, restraint, and perspective together. That does not make someone holy, of course. But it may help explain why a person at 40 can often carry complexity better than they could at 22.

Psychology says something similar. One influential account of adult development describes the years from 30 to 45 as “established adulthood.” I find that phrase striking, because it names what many people feel but cannot quite articulate. This is often the season when life stops being mainly exploratory and becomes weight-bearing. One has commitments. One has consequences. One has a history now. Perhaps children, perhaps grief, perhaps real failures, perhaps a marriage that has had to be forgiven through seasons, perhaps parents aging, perhaps work that has become vocation—or disappointment. These are not small things. They shape the soul. Research suggests that this period is often one of growing expertise, increasing responsibility, and a different kind of cognition—not simply solving problems, but learning what the real problems are. And that shift matters spiritually.

Because mysticism, in the Christian sense, is not fantasy. It is not religious intensity for its own sake. It is not merely collecting unusual experiences and calling them holy. Christian mysticism is about union with God, surrender to divine love, purification of the heart, and learning to see reality truthfully in Christ. That path requires tenderness, yes, but also patience, self-knowledge, endurance, and a willingness to let God strip away illusion. By 40, many people have suffered enough to stop confusing excitement with depth. They have loved enough to know love costs something. They have failed enough to become less arrogant about themselves and more compassionate toward others. That kind of ripening does not automatically make one a mystic. But it does prepare the ground.

And yet, we should be careful not to romanticize 40 too neatly. The research on spirituality across adulthood suggests that spiritual deepening is often gradual and may intensify even more in the 50s and beyond. One longitudinal study found significant increases in spirituality especially from the mid-50s into older adulthood. That makes sense to me. There is a second kind of surrender that comes later in life, when mortality is no longer theoretical. So if someone is 28 and hungry for God, they need not wait. If someone is 63 and only now awakening, they are not late. The Spirit is not trapped by developmental stages.

The same is true when we look at mystical experience itself. Some studies suggest that reports of mystical-type experience are not limited to middle age at all, and may even be more common in younger cohorts in some respects. Other work suggests that spirituality and mystical experience are associated with a kind of transcendent wisdom across age groups, not just among older adults. So the ability to encounter mystery is not owned by 40-year-olds. A young saint may burn with divine love. A child may glimpse wonder more naturally than a scholar. But there is still a meaningful distinction between having a mystical moment and bearing it well. Age may not grant the experience, but it can help with the integration.

This, I suspect, is where the old religious symbolism of 40 still speaks to us. In Scripture, 40 is so often the number of testing, purification, preparation, and completion. Forty days in the flood. Forty years in the wilderness. Forty days on the mountain. Forty days of fasting. In the biblical imagination, 40 is not just arithmetic. It is the measure of a soul being prepared. And in Islamic tradition, Muhammad is traditionally said to have received his prophetic calling at age 40. Across traditions, 40 has often meant ripeness—not perfection, but readiness.

As a Christian, I would say it this way: by 40, many people have been in the wilderness long enough to start recognizing the voice of God there.

They have discovered that ambition does not save, that admiration does not satisfy, that pleasure cannot carry the whole weight of a human life, and that control is mostly an illusion. This can be a painful discovery. But it can also be mercy. The soul often begins to open when its false securities begin to fail. That is one reason 40 can feel spiritually significant. It is often the age when a person becomes willing—not merely curious, not merely spiritual, but willing. Willing to pray more honestly. Willing to repent more deeply. Willing to stop performing. Willing to be led into silence. Willing to belong to God.

So no, research does not prove that 40 is the age when you are “fully mature” and can finally be a mystic.

But it does give us something gentler and more human: the sense that around 40, many people reach a season of greater inward integration, heavier responsibility, deeper self-knowledge, and more serious meaning-seeking. And from the standpoint of Christian mysticism, that combination can become fertile soil for contemplation. Not because God was absent before. Not because youth cannot be holy. But because there comes a point in many lives when the soul is less interested in sparkle and more ready for fire.

And that may be the beginning of wisdom.

Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC3621648/
https://www.brainfacts.org/thinking-sensing-and-behaving/aging/2018/when-the-brain-starts-adulting-112018
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=5649&context=facpub
http://www.psychology.hku.hk/ftbcstudies/church/images/docs/Wink_Dillon_2002.pdf
https://pubmed.ncbi.nlm.nih.gov/8375680/
https://www.cambridge.org/core/journals/ageing-and-society/article/age-differences-in-spirituality-mystical-experiences-and-wisdom/44C60E8A9E2CD5AB1CC00C6FF044A4BA
https://www.thetorah.com/article/forty-a-biblical-symbol-for-completeness
https://www.britannica.com/biography/Muhammad