First, the Corinthians were
washed. The imagery of washing was naturally inspired by the fact that baptism
is a water rite. The image stands for cleansing, from the sins of the past. The
introductory 'but' in 'but (αλλα) you were washed ...' contrasts the clause to
the list of vices in the preceding vv. 9f. Before becoming Christians the
Corinthians are said to have indulged in idolatry, adultery, etc. But the
context also suggests that the vices represent not only various sinful actions
in the past which are now forgiven, but also earlier, basic conditions of life
which were dictated by evil powers and paganism. From those conditions the
addressees are now liberated.
Secondly, entrance into the church
meant that the Corinthians were 'sanctified'. Already at the beginning of the
letter Paul addressed them as 'the church of God', 'those sanctified in Christ
Jesus, the holy, called ones' (1 Cor 1.2). To be holy means that a person or an
object belongs to God and to the realm which is reserved for and dedicated to
him. There he is also present in a particular manner. Therefore the holy person
or the holy object is separated from the secular world (see e.g. Rom 12.2; 1
Cor 5.9f; Gal 1.4). It behooves those who belong to this divine sphere to be
holy, i.e. to live in a manner which is worthy of the divine. According to 1 Corinthians
6 the opposite has occurred when the Corinthians' conduct is incompatible with
their holy state.
Thirdly, the transition from old to new is characterised by the phrase 'you were justified' (εδικαιωθητε). In the context it is contrasted to verse 9, which claims that 'unrighteous (or: unjust, αδικοι) people will not inherit the kingdom of God'. To have been 'justified' here means that the transgressions of the past have been forgiven. But we should also allow the whole of Paul's thinking on justification to colour our understanding of the passage. The entrance into the church of God meant that the Christian was delivered from the power of sin and entered a realm where God's creative Spirit held sway. The fact that all the verbs in the passage are in the passive voice implies that the underlying agent is God. It is he who cleanses, sanctifies, and justifies. Paul expresses the same opinion in other places when dealing with people's entering the church. The entrance is actually performed by God: people are 'called' (see 1 Cor 1.26; 7.18ff, etc.), and God is the one who calls (cf. the active use in Rom 8.30; 1 Cor 7.17; Gal 1.6; 1 Thess 2.12).
Finally, the washing, the sanctification, and the justification are said to have taken place 'in (or: through) the name of the Lord Jesus Christ and in (or: through) the Spirit of our God'. Probably the first half of the phrase echoes a baptismal formula. Above, we saw that the meaning was probably the same whether one said 'baptise into the name...' or 'baptise in the name ...'. Thus it also fits well into this context to assume that 'the Lord Jesus Christ', that which he has done, and that which he means in the present, are the foundation of the baptism and of the other phases of the entrance into the church. They make it meaningful to speak of a cleansing, of being sanctified and dedicated to God, and of being justified in the profound, Pauline sense of the word.(Lars Hartman, "Into the Name of the Lord Jesus": Baptism in the Early Church [Studies of the New Testament and Its World; Edinburgh: T&T Clark, 1997], 64-65)