Consider the preceding verse 18. It states that Jesus has fulfilled what was spoken of by the prophets. Next we see instruction given that again parallel Peter's initial message at Pentecost; "Repent, and be baptized in the name of the Lord Jesus for the mission of sin and you shall receive the gift of the Holy Ghost. (indwelling presence of the Lord)
Acts 3:18-19
18 But those things, which God before had shewed by the mouth of all his prophets, that Christ should suffer, he hath so fulfilled.
19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;
12And when Peter saw
it, he answered unto the people, Ye men of
israel why marvel ye at this? or why look ye so earnestly on us, as though by our own power or holiness we had made this man to walk?
13The God of Abraham, and of Isaac, and of Jacob, the God of
our fathers hath glorified his Son Jesus; whom ye delivered up, and denied him in the presence of Pilate, when he was determined to let
him go.
14But ye denied the Holy One and the Just, and desired a murderer to be granted unto you;
15And killed the Prince of life, whom God hath raised from the dead; whereof we are witnesses.
16And his name through faith in his name hath made this man strong, whom ye see and know: yea, the faith which is by him hath given him this perfect soundness in the presence of you all.
17¶And now, brethren, I wot that through ignorance ye did
it, as
did also your rulers.
18But those things, which God before had shewed by the mouth of all his prophets, that Christ should suffer, he hath so fulfilled.
19Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; ( FUTURE )
20And he shall send Jesus Christ, which before was preached unto you:
21Whom the heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the wor