Acts 18:25

‘This man had been instructed in the way of the Lord, and being fervent in spirit, he spoke and taught accurately the things concerning Jesus, knowing only the baptism of John.'

It would appear that Apollos had either visited Jerusalem and come under the ministry of John the Baptiser, or that he had come under the influence of others who had done so. As a result of that ministry they had learned of the coming of Jesus, and even something of His life and teaching. We learn here that Apollos had been instructed in ‘the way of the Lord'. This reminds us of the words cited by John, ‘make ready the way of the Lord' (Luke 3:4). Apollos had taken in John's instruction.

Furthermore he knew and taught accurately ‘the things concerning Jesus'. We must probably read this as meaning ‘the things concerning Jesus as taught by John'. He had been so inspired by it that he had taken up a teaching ministry so as to press it home to Jews everywhere, and prepare them for the arrival of the Coming One. Unfortunately we are not given full details of what he did know and believe. But we can be sure that he knew nothing of the saving effects of Jesus' death and resurrection, nor of the coming of the Holy Spirit in power. Otherwise he would not have needed to be taught more.

‘Fervent in spirit.' Almost there, but not quite. His own spirit was the source of his effectiveness, even though strengthened by God. Possibly he had similar inspiration to others prior to Pentecost, which could include being ‘filled (pimplemi) with Holy Spirit' (Luke 1:15; Luke 1:41; Luke 1:67) to speak inspired words. Thus ‘being fervent in spirit he spoke and taught'. But it was pre-Pentecost filling.