1. How shall they hear without a preacher who preaches Jesus as the Christ! (Rom 10:14-15)
    Acts 8:31-35, Lk 24:25-27, Lk 24:44-45

People don’t know unless we explain the Old Testament and explain that Jesus is the Christ. (Acts 8:31-35, Rom 10:14-15)

Acts 8:31 And he said, How can I, except some man should guide me? And he desired Philip that he would come up and sit with him.
32 The place of the scripture which he read was this, He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened he not his mouth:
33 In his humiliation his judgment was taken away: and who shall declare his generation? for his life is taken from the earth.
34 And the eunuch answered Philip, and said, I pray thee, of whom speaketh the prophet this? of himself, or of some other man?
35 Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.

Rom 10:14 How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?
15 And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!

Even the disciples who were with Jesus did not know that Jesus was the Christ. Eventually, the resurrected Jesus explained the Old Testament to his disciples, showing that he was the Christ. (Lk 24:25-27, Lk 24:44-45)

Lk 24:25 Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken:
26 Ought not Christ to have suffered these things, and to enter into his glory?
27 And beginning at Moses and all the prophets, he expounded unto them in all the scriptures the things concerning himself.

Lk 24:44 And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me.
45 Then opened he their understanding, that they might understand the scriptures,