Peter's foundational preaching in the earliest days of the church provides a model for preaching to every generation. It must be practiced in the power of the Holy Spirit, as the natural outflow of a life lived for and empowered by the presence of God, humbly submitted fully to him. It must be authentically proclaimed by one who has first personally come under the convicting power of God's truth and also responded in repentance and received God's forgiveness. And the message must always be Christ-centred, gospel focussed, rooted in Scripture, and relevantly applied to contemporary circumstances. The response to such preaching is in the hands of a sovereign God, and all the glory is his.
A Legacy of Preaching, Vol 1 (p.61f)