AN ARTICLE that I read recently called the baptism of Jesus “a delicate problem of apologetics”. To understand Luke’s version, we must decide whether he is using Mark only, or another source as well. Differences in detail between Mark and Luke may suggest two sources. But when, for example, we notice that Luke and Matthew say the heavens were “opened” (toning down Mark’s more violent “heavens split apart”), it may be that both later writers thought Mark’s language crude, and “improved” it.

There is reason, then, to think that Luke is tweaking Mark, not following another source. But the absence of the Baptist is still puzzling. He is mentioned at the beginning of the lection, as is his imprisonment. But he is not recorded as being present at Jesus’s baptism, never mind as having himself been the Lord’s baptiser.

The article that I mentioned sees this as Luke’s solution to the “delicate problem”. Matthew made John express a concern about the theological proprieties, so that Jesus could reassure him (3.14-17). Instead, Luke sets John aside. By mentioning John’s imprisonment before Jesus’s baptism, Luke even provides a reason for his absence from the baptism itself. This is ingenious. It may even be right. But the ingenious solution creates a problem of its own: if not John, then who did baptise Jesus? Before we tackle this, we must scrutinise more of the detail of Luke’s account.

The fact that the descent of the Spirit happens not at the baptism but after it supports the ingenious solution. Jesus has begun to pray after his baptism, without being told by anyone to do so. It looks like a natural and instinctive response to that water baptism. The water baptism is separately (and, for now, uniquely) followed by a descent of the Spirit upon Jesus. There is at least a hint — possibly more than a hint — that it is the descent of the Spirit which “really” matters in Luke’s mind. After all, hundreds of people had received water baptism. Only one, the Lord, receives this Spirit baptism.

At this point, John’s Gospel offers further insight; for his approach is different again. He does not mention Jesus’s baptism at all. Yet, as often in John, important things are referred to only obliquely. Unlike Luke, John does not play down the part played by the Baptist. Instead, he weaves it even into his prologue, giving the greatest possible prominence to the part played in God’s plan by this holy man.

John tells us repeatedly that the Baptist baptises with water. Thus far, he is in agreement with Luke: (John 1.26) “I baptise with water”; (1.31) “I came baptising with water”; (1.33) “the one who sent me to baptise with water said to me, ‘He on whom you see the Spirit descend and remain is the one who baptises with the Holy Spirit’.”

Instead of excluding the Baptist from participating in the Spirit’s descent through baptism, John’s Gospel makes him the prophet of the Spirit’s descent, a witness to the Spirit’s descent, and — most distinctive of all — the person who gives a first full expression of the water/Spirit distinction.

There is something almost Britishly self-deprecating about the way in which Jesus is protected — by all the Evangelists — from having to trumpet his own importance. It makes me think of the conferring of holy orders. The support and confidence of sending congregations, not the personal conviction of the candidate, turn a postulant into an ordinand.

Does this mean that baptism was unimportant to Luke? No one who has read the Acts of the Apostles could think so. It is historical fact that the visible sign of baptism— water — continued to be essential to the ritual (for want of a better word), and also that the elements of water and Spirit were as fixed and essential in Luke’s time as in ours.

Luke’s ingenious solution to the “delicate problem” helps by reminding us that, in what we call a “sacrament”, the bit that matters most may be the invisible reality being signified — yet, without the visible reality, the sign is null and void. Again, holy orders illuminate: the personal qualities of an individual priest are irrelevant to the validity of the sacraments that they celebrate. Here, finally, is confirmation of Luke’s ingenious solution: for him, the question who baptised Jesus is irrelevant. The sacrament, not the human effecter (for want of a better term), is what matters.