This is the recommendation Deb Matlock and Richard Jurin make in Spirituality and Sustainability Education: A Natural Partnership, their essay about what spirituality means within the practices of sustainability education and environmental education.
In their essay, Matlock and Jurin encourage practitioners to leave enough room in their programs to provide individuals an opportunity to process their outdoor experiences. They explain that "processing space is essential as it allows for more awareness and deeper contemplative thinking." They go on to say that, while practitioners may feel their program inspires participants to form new connections with nature and place, participants are going to have spiritual experiences when they are ready. The best thing practitioners can do is build space into their programs that allow for such experiences to happen.
Matlock and Jurin also share what they learned from the focus groups and conference sessions they have led about spirituality. To learn more about their work on spirituality and the role it plays in sustainability education, purchase a copy of Spirituality and Sustainability Education: A Natural Partnership from the journal Sustainability.
Matlock, Deb and Richard Jurin. (2016). Spirituality and sustainability education: A natural partnership. Sustainability: The Journal of Record. 9(6): 276-282