Acts 28:31

Preaching the kingdom of God
That is, the Gospel, as in ( Luke 4:43 ) ( 16:16 ) ; he preached up Jesus as the King Messiah, and declared that his kingdom was come, and opened the nature of it; that it consisted not in meats and drinks, but in righteousness and peace, and joy in the Holy Ghost; which is the kingdom of grace here, and is within a man, in his heart, where grace reigns through righteousness, unto eternal life: and he gave them same account of the kingdom of glory, and the way unto it; and showed, that without regeneration and sanctification, no one could be meet for it; and without the justifying righteousness of Christ, no man could have a right unto it, or be possessed of it:

and teaching those things which concern the Lord Jesus Christ:
his person, as God and man; his office as Mediator, being prophet, priest, and King; his incarnation and birth; his life and miracles; his doctrine and obedience, sufferings and death; his resurrection, ascension, session at God's right hand; his intercession, and second coming to judgment; with all the truths of the Gospel, in which he has a concern; as redemption, peace, reconciliation and pardon, by his blood and sacrifice, and justification by his righteousness, and salvation and eternal life through him. These things had been the subject of the apostle's ministry, throughout the whole of it: he began at Damascus with preaching Jesus as the Son of God and the true Messiah; and he ends at Rome, with teaching the things concerning him: at his first setting out in the work of the Lord, he determined to make known none but Christ, and him crucified; and in this resolution he continued through the whole course of his life, and abode by it to the end: and this he did

with all confidence;
with all freedom and liberty in his soul, though he was bound in his body with a chain; with all plainness, openness, and faithfulness; and with all courage and boldness, though in the midst of adversaries:

no man forbidding him;
not the Roman emperor, nor the Roman senate, nor any other magistrate; nor could the Jews hinder him, nor was his mouth to be stopped by any; nor could the open door of the Gospel be shut, or its course be impeded; for though the apostle was bound, the word of God was not, but ran and was glorified; and was made known, and even owned in Caesar's palace; some say Nero's cupbearer, and Poppea his concubine, were converted by him: and he not only continued preaching the Gospel during the two years of his imprisonment at Rome, but also wrote several epistles to churches, and particular persons; as the epistles to the Galatians, Ephesians, Philippians, Colossians, and the Hebrews, and to Philemon, and the "second" epistle to Timothy: some copies add here, "Amen"; and at the close of the Alexandrian copy, stand these words, "the Acts of the holy Apostles"; and at the Syriac version these, "the End of the Acts of the blessed Apostles, that is, of their Histories".