A couple of weeks ago in our Zoom church meeting, Jim shared some thoughts about the line of a song – ‘the breath in our lungs’. He went on to explain why breath is so important – breath gets oxygen into our body, which every single cell needs in order to release energy and to keep us alive. As a Biology teacher this got me thinking about some of the lung volumes I teach in A-level Biology – in particular tidal volume and residual volume. Tidal volume is the volume of air we take in (or out) of our lungs with each breath at rest – it is this that replenishes the oxygen to be transported around the body. However, we also have something called residual volume - which is the volume of air that is always present in our lungs and can never be removed. No matter how hard we breathe out we can never completely empty all of the air from our lungs. This small volume of air in our lungs keeps the air sacs open and allows efficient transfer of oxygen into our blood stream – without it the air sacs would collapse and we would not be able to extract the oxygen we need from the air no matter how much we breathe in. In the same church meeting we discussed how the Spirit is sometimes referred to as 'the breath of God'. When we become a Christian we receive the Spirit, similar to a baby taking it’s first cry and filling it’s lungs for the first time. I like to think of the Spirit as our residual volume – the breath in our lungs that is keeping everything open and efficient, that we can never get rid of, and is enabling us to get the most out of every breath that we take. Even when we feel breathless or empty, the breath of God is still there in each and every air sac and will never be expelled.