Greek: 19 μετανοήσατε οὖν καὶ ἐπιστρέψατε πρὸς τὸ ἐξαλειφθῆναι ὑμῶν τὰς ἁμαρτίας, ὅπως ἂν ἔλθωσιν καιροὶ ἀναψύξεως ἀπὸ προσώπου τοῦ κυρίου 20 καὶ ἀποστείλῃ τὸν προκεχειρισμένον ὑμῖν Χριστόν, Ἰησοῦν, 21 ὃν δεῖ οὐρανὸν μὲν δέξασθαι ἄχρι χρόνων ἀποκαταστάσεως πάντων ὧν ἐλάλησεν ὁ θεὸς διὰ στόματος τῶν ἁγίων ἀπ’ αἰῶνος αὐτοῦ προφητῶν.
My Translation: 19 Y'all must repent, therefore, and y'all must turn about towards the blotting out of your sins, so that the cooling seasons may come from the face of the Lord, 20 and he may send the Christ he chose to you, Jesus, 21 who the sky surely must accept until the time of everything's reconstitution, of which God has spoken, from his Eon, through the mouth of the holy prophets.
KJV: 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. 20 And he shall send Jesus Christ, which before was preached unto you: 21 Whom 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 world began.
My translations are purposefully stretched and should not be viewed as more accurate than the KJV translation unless I say so in the post. I'm trying to show the range lying between the original Greek text and the English.
I have not yet begun work on a post to discuss this Scripture Mastery selection, but I've posted up my translation until I finish the post.