There are various ways of thinking about the sacraments. Over the centuries, Christians have tended to drift into two opposite errors concerning them: either to elevate them to the status of magical rituals, or (sometimes as an over-reaction to the first error) to dismiss them as optional extras, unimportant and non-essential.
In the past, some churches have taught that simply to be baptised (even unwillingly) is enough to make someone a Christian. “[The sacraments] are said to benefit all men, even the godless and unbelieving, provided they do not put an ‘obstacle’ in the path of grace – as if such unbelief were not in itself the most obstinate and hostile of all obstacles to grace.” (Luther: The Babylonian Captivity of the Church) Aside from the rather obvious fact that this doesn’t seem to work in a lot of cases (such reasoning would make Hitler and Stalin fully paid-up Christians), if such power is said to reside in the rites themselves, then the distinction between belief and unbelief is abolished. And yet faith is more powerful (and more important) than any sacrament (I Corinthians 1:17).
So are they merely symbolic? I used to think so when I first became a Christian, because that was the church tradition that I first encountered. But I have come to the conclusion, on careful reflection, that there must be more to them than this. Whether a symbol is present or not makes no difference to the underlying reality: some days I wear a small cross, some days I don’t, and my faith is unchanged by its presence or absence. But the sacraments are not optional: Jesus commanded His followers to baptise converts and to remember Him with bread and wine!
So I have moved towards the middle of the spectrum. I believe that the sacraments are shadows – reflections in the material, visible world of what actually happens in the spiritual realm. The shadow can exist only because the substance does, and any genuine substance will cast a shadow: just as there is ‘no smoke without fire’, so the shadow bears witness to the existence of the substance. And as long as we live in the material world we have to express our faith in that world – by doing visible, physical things. The objective physical reality of the sacraments helps to prevent our faith from becoming too cerebral and subjective.
The modern Western world generally gets by without much use of symbolism, and perhaps the last remaining secular equivalent of a sacrament is a wedding ring. This is a symbol of the marriage relationship, not the relationship itself; yet the giving of the ring is the key moment of the wedding ceremony, and in most people’s minds it is so closely associated with the marriage that it would be unthinkable for a married woman not to wear it.