(a) Peter's speech on Pentecost day (Acts 2):
(i) At Pentecost, the disciples were filled .with the Holy Spirit and spoke in tongue
(ii) The crowd around was surprised at what they saw and heard while others allege that the disciples were drunk.
(iii) Peter addressed the crowd that it was too early to get drunk.
(iv) It was rather the fulfillment of Joel's prophecy that in the last days God would his spirit upon all flesh.
(v) Then their sons and daughters would prophesy, men would have visions and old men dream dreams.
(vi) And those who would call upon the name of the Lord would be saved.
(vii) He said Jesus was crucified by lawless men according to the plan and foreknowledge of God.
(viii) But God raised Christ from the dead, loosening Him from the pangs of death.
(ix) For the scripture (Psalm of David) maintained that the Holy one's soul would not be abandoned in Hades, nor see corruption.
(x) He said that when David died and was buried, his tomb was still there.
(xi) As a prophet, David spoke about the resurrection of Jesus.
(xii) According to Peter, God raised up Jesus and exalted him at His right hand.
(xiii) Further, Jesus received from the Father the promise of the Holy Spirit and poured it on the disciples.
(xiv) Peter further declared that God had made Jesus both Lord and Christ.
(xv) The crowd was cut to the heart, asking Peter, "Brethren what shall we do?
(xvi) Peter asked them to repent and be baptized in the name of Jesus for the forgiveness of their sins.
(xvii) And that the gift of the Holy Spirit was promised to them and later generations.
(xviii) Hence, they should save themselves from this crooked generation.
(xix) The crowd responded favorably such that three thousand people were baptized.

(b) Three changes in the life of the disciples:
(i) The disciples spoke in tongues as an empowerment of the Holy Spirit.
(ii) They no more feared the religious leaders but became bold and courageous.
(iii) They boldly talked about Jesus as the expected Messiah who had resurrected preached freely.
(iv) They started winning/converting souls into Christianity.
(v) Most of them began to prophesy.
(vi) They performed signs and wonders- healing, exorcising etc.
(vii) They became more humane, affable, generous and caring for the poor and the aged.
(viii) They lived a communal life.