Throughout Scripture God attaches special importance to certain 'things'. There are the trees of life and of the knowledge of good and evil. There is the rainbow after the Flood and perhaps the dove's olive branch too. There is circumcision, Moses' rod, the fiery, cloudy pillar, the holy mountain, thunder and lightning, the Sabbath Day, the tabernacle, its sacrifices and its furniture, the Temple and the ark of the covenant. We could speak of the bronze snake, Samson's jawbone and Elijah's cloak.
We turn to the New Testament and think of baptismal water, of the mud and spittle in Jesus' ministry, of the bread and wine, of Peter's shadow and handkerchiefs touched by Paul. One could include too the miracles of the Lord and the apostles.
We can think of words, and the Word.
We can think of the incarnate life of the Son of God.
Now this makes an unequal collection but it is nonetheless true that in some way God uses in these cases some element of creation in a way that distiguishes it from the rest of creation - at least for a time.
We might identify the purposes for which these 'things' are used as being one or more of the following:
1. As a pointer - or sign as it is more commonly called. An earthly thing is used as a signpost to something heavenly. Our minds are not to stay on the earthly thing (sign) but look to the heavenly thing to which the sign points. It is a signpost. It is a ladder, one might say, to enable us to climb to heaven; or a glass through which to look on spiritual realities.
2. As a picture which in some way illustrates the heavenly reality. For example it is easy to see why bread and wine bring to mind the body and blood of Christ or water the cleansing and death-and-resurrection of incorporation into Christ.
3. As a pledge or as we might say a 'seal'. The thing is in some way an assurance and guarantee to the recipient of the spiritual blessing it represents, as was circumcision to Abraham of his righteousness by faith.
4. As a means of participation, so that by means of the 'thing' the recipient receives something of the heavenly reality, namely, and supremely, Christ in his presence and power and in all his fullness and his benefits. This is the highest use of 'things'.
5. Finally the thing may be an instrument by which the Lord accomplishes something, for example the rod of Moses and the weapons of Samson and the cloak of Elijah.
Now the list of 'things' above is very uneven. Some are specifically called signs such as circumcision, the rainbow and the Sabbath -signs of the covenant relationship between God and Israel. Others are signs of his saving work such as the sacrifices and the bronze serpent. Others again are signs of his presence and dwelling with men - the tabernacle, the Temple and the ark of the covenant. Yet others are signs of his sovereign working and rule over creation in the interest of redemption - the rod of Moses, for example, over a long period; or as a'one-off', like Peter's shadow.
Now where does this take us?
1. In the continuing church of the New Testament we see the simplification of the use of things by God. We have the bread and wine and the water of baptism.
What of the Word? The Word of God is also a creation which God takes up and uses. It is a unique creation as it is uniquely inspired but it is still ineffective until the Spirit of God takes it and applies it. Yet the principles above apply; it is a pointer to the things of which it speaks, an illuminator of spiritual realities, a pledge and guarantee that the recipient will receive the spiritual reality promised and the means of participation in that reality. It is also of course an instrument in God's hand to accomplish his purposes.
2.What is the relation between the created thing and the heavenly reality it represents - or as we say between the sign and the thing signified? We have to be careful not to say that God attaches himself to the thing in any way that could render the effectiveness of the thing automatic. A created thing never becomes in any sense divine. Yet we must not go to the other extreme and suggest that the only efficacy of the sign is in God's more or less arbitrary choice to render it effective in such a way now and not then, for 'him' but not for 'her', here and not there. There is a stronger link between the sign and the thing signified than that.
What that link is, is frankly a mystery and one without analogy in the natural realm. Some call it a 'sacramental union', confess it is a mystery and are content to leave it at that. Others push it in one of the two directions indicated - towards a magical ex opere operato view, or alternatively a view that renders the use of the means virtually incidental to the sovereign work of God's Spirit.
Both extremes distort the nature of the relationship God has set up between sign and thing signified.
It is the same with the Word as with the sacraments. Although we cannot say that the Word on its own is enough, or that the Word automatically accomplishes an effect, we must not give the impression either that the sovereignty of the Spirit means that there is no promise attached to the preaching of the Word other than the hope that God may use it. God uses 'mechanical' pictures from nature - rain and snow falling and producing fruitfulness on earth - to illustrate what we may expect of the word preached - Isaiah 55:10,11. The Word 'will not return to me empty but will accomplish what I desire and achieve the purpose for which I sent it'.
Further, the effect we hope for may not be that which the Word accomplishes. Paul speaks of the gospel being sometimes a fragrance of life, at other times an aroma of death (2 Cor 2:14-16). Either way, the Word is not being ineffective.
There is a relationship therefore between the created element God takes up and the effective work of God which he has established in the particular cases that we call the Word and the sacraments, which is unique. These things are different from other created things when in their proper use, as a silver coin is different from a strip of silver - it has a value given it by the minter ( yet not a value that inheres in the sign - all illustrations are dangerous!). It is neither automatic nor is it the arbitrary exercise of divine sovereignty; in asserting the essential presence of God's Spirit we must not deny this union nor in asserting the union must we deny the necessity of the Spirit.
Could God do all he wants without means or signs or 'things'? Of course; no -one doubts it. The point is , however, that normally he chooses to work, and represents himself in Scripture as working, by such means.
3. We see at least some analogy of the 'sacramental' union in the hypostatic union, the union of the divine and human in Christ. Here the union of divine and created is perfect and permanent. The taking up of creation by God reaches its zenith in the incarnation . Here is the human nature of Christ , body and soul, taken up into the person of the divine Son, to be all that creation can be in the service of God. Pointer, picture, pledge, participation and instrument of the presence of God in all his blessings and benefits are in Christ incarnate. Calvin's doctrine of the sacraments does justice to this better than any other, in insisting that the fellowship with Christ in Word and sacrament is with his body as well as in Spirit - a spiritual fellowship and a heavenly one, mediated by the Spirit, but nonetheless fellowship with his body for, as Sinclair Ferguson insists, this is the only Christ there is. A mystery? Yes, Calvin would say so. But whether in the preaching of the Word whereby people are mysteriously converted in the combination of Holy Spirit power and human instrument, or in the person of Christ himself, glorified and in heaven in his human body, God's use of 'things' to give himself to sinners is all mystery, and all glorious.