A Higher Power is anything that has more power than one person contains within themselves. Some people in Alcoholics Anonymous have found that the group works very well as a Higher Power. For them, GOD = Group of (recovering) Drunks. I don’t see any conflict in being atheist and highly spiritual at the same time. Science is enormous, infinitely powerful, and truly unfathomable. The more we learn, the more realize we don’t know. Human beings are part of a grand scheme, an enormous system in which every part has the potential to impact every other part. Whether or not the future in that scheme is predetermined doesn’t necessarily matter.
So how does an atheist connect with their Higher Power? By being at one with the environment: people, places, things, the earth, the sky, etc. Prayer is a central tenet of many religions. Prayer is a way for people to connect with and get guidance from their Higher Power. Can prayer work for atheists? It can and will if you replace the word prayer with mantra, self-talk, or any other term that designates a conscious effort to focus our thoughts on something positive. There’s plenty of evidence to suggest that what we tell ourselves determines how we interpret the world, how we feel, and how we behave. All this, in turn, has the potential to positively or negatively impact our own well-being and the world around us.
Our environment has a direct impact on our internal systems - Sunlight, gravity, diet, human touch, to name just a few examples. People who pay attention know when they are going with the flow or fighting the current. I suggest that spirituality for atheists involves being in touch with the environment, and putting energy into things that are fed by the environment rather that in conflict with it. Approaching life in this way has the potential to create a deep sense of serenity. What could be better than that?