Sometimes as a teacher there are complicated things to cover which stretch a pupil’s ability to understand. But often, it’s grasping the basics which proves more arduous. The things that we should grasp quickly and build on can seem elusive to us.

Yesterday in the snow, local schools shut early, and I had the pleasure of doing some easy science experiments with my grandchildren, one being the simple test using pH paper to determine if a liquid is an acid or an alkali. We poured liquids onto these magic strips of paper in a petri dish and watched the paper change colour, checking the colours on a chart to conclude that lemon juice is an acid and milk is an alkali.

Now understanding why and how this happens may be more complicated, but the instantaneous change was easy enough for even my four-year-old granddaughter to grasp.

It made me think about what we call the ‘litmus test’ or ‘acid test’ in other areas, meaning a simple way of determining something. I was reminded of Jesus’s words, ‘by this everyone will know that you are my disciples, if you love one another.’ (John 13:34)

Love is the simplest way of testing the reality of our faith. It’s so simple even a child can do it. Yet it’s something that adults often fail to grasp. We add on lots of complicated things and can then forget the basics.

So today, the challenge before every disciple of Jesus is to love others as the outworking of our love for God. It’s simple but profound. Love God. Love people. Even your enemies.