"Root and branch" is an ancient Hebrew expression, but one that is easily understood today. The “roots and branches” of something represent its entirety, just as the roots and branches of an actual tree represent the whole plant – as when we read in the Book of Job “His roots dry up below and his branches wither above” (Job 18:16), or in Malachi “…Not a root or a branch will be left to them” (Malachi 4:1).
Sometimes the expression can also mean the beginning and end, the past and future, as when it is used metaphorically to represent Christ himself as the “Root and branch” – the one who both lived before and was also the descendant – of David, the son of Jesse (Revelation 22:16).
But let’s go back to the basic meaning of “root and branch” meaning “the whole thing” or “every part.” It’s a simple metaphor for completeness that can remind us of an important lesson in Christian living. When we read how Jesus told his disciples “If your hand or your foot causes you to stumble, cut it off and throw it away…” (Matthew 18:8), we understand that this does not mean literally, and that Christ was talking about sin rather than literal body parts. But we may miss the fact that “hand and foot” was a parallel expression to “root and branch” – it could mean every part of something. Christ’s clear teaching was that we should become perfect (Matthew 5:48), and sin must be cast out of our lives in its entirety – no part of it must remain in us.
Now let’s take that understanding back to the idea of “root and branch.” Most people know that if you cut down a tree you must also dig out the roots or the plant may grow back up from the roots left in the soil. But it is also true that if we cut down a tree and even dig out the roots, but leave some of the branches lying around on the ground, sometimes the branches may produce roots from which the tree will grow again.
What does all this have to do with Christian living? Simply that we must always remember that sin must be torn out of our lives “root and branch” or, like a partially cut down tree, it will return again. Digging out the roots of sin is equivalent to removing the thoughts that initiate the growth of sin in our minds. If we remove the outward visible branches – for example, pornographic materials from our home – the problem will still grow back again if the wrongful thoughts are not completely removed from our minds. In the opposite way, even if we decide, for example, that we will turn from alcohol dependency, but we leave “branches” such as wine “for cooking” around our home, it will only be a matter of time before those “branches” take root again as they initiate thoughts – the “roots” of the problem – in our minds.
These examples are obvious ones, but the principle applies in many situations. As the apostle Paul wrote: “A little yeast works through the whole batch of dough” (Galatians 5:9 and 1 Corinthians 5:6). Leaving either a few roots (thoughts) or a few branches (anything that triggers the thoughts) in our lives will result in the problem growing back again. There is only one way to fully put a sin out of our lives – it has to be removed “root and branch.”