Had been instructed in the way of the Lord (hn kathchmeno thn odon tou kuriou). Periphrastic past perfect passive of kathcew, rare in the old Greek and not in the LXX from kata and hcew (hcw, sound) as in Luke 1:4 , to re-sound, to re-echo, to teach by repeated dinning into the ears as the Arabs do now, to teach orally by word of mouth (and ear). Here the accusative of the thing (the word) is retained in the passive like with didaskw, to teach (Robertson, Grammar, p. 485). Being fervent in spirit (zewn twi pneumati). Boiling (from zew, to boil, old and common verb, in N.T. only here and Romans 12:11 ) like boiling water or yeast. The Latin verb ferveo means to boil or ferment. Locative case after it. Taught carefully (edidasken akribw). Imperfect active, was teaching or inchoative, began teaching, accurately. He taught accurately what he knew, a fine gift for any preacher. Only the baptism of John (monon to baptisma Iwanou). It was a baptism of repentance (marked by repentance) as Paul said ( Romans 13:24 ; Romans 19:4 ), as Peter said ( Romans 2:38 ) and as the Gospels tell ( Mark 1:4 , etc.). That is to say, Apollos knew only what the Baptist knew when he died, but John had preached the coming of the Messiah, had baptized him, had identified him as the Son of God, had proclaimed the baptism of the Holy Spirit, but had not seen the Cross, the Resurrection of Jesus, nor the great Day of Pentecost.