The vast and growing challenges for human health and all life on Earth require urgent and deep structural changes to the way in which we live. Broken relationships with nature are at the core of both the modern health crisis and the erosion of planetary health. A declining connection to nature has been implicated in the exploitative attitudes that underpin the degradation of both physical and social environments and almost all aspects of personal physical, mental, and spiritual health. It is increasingly clear that the entwined challenges of biodiversity loss, climate change, and human health cannot be addressed without addressing selfishness, greed, apathy, and the value systems that created these global problems. Calls for a spiritual and cultural transformation recognize that “inner” development is important and necessary for meaningful “outward” transitions with a shared purpose for wiser, more sustainable societies. Many of these emotional and spiritual assets appear to be facilitated by a connection to nature, which is also strongly associated with community cohesion, prosocial attitudes, and pro-environmental actions. Restoring the human connection to nature may therefore provide a critical common pathway to promote the physical and spiritual wellbeing of individuals and communities as well as personal and social environmental responsibility. In this paper, we summarize and reflect on the discussions of the Nova Network planetary health community with respect to nature-based solutions as pathways to promote both personal and planetary health with a more mutualistic mindset. These discussions spanned biological to psychological interactions with nature—including the critical relationships with environmental microbes that influence the physical, emotional, and behavioral aspects of health. We consider the ways in which stronger relationships with nature promote “inner assets” to support “outward actions” for personal and planetary health.