William Burkitt on Acts 16:34

See here a special evidence and sweet fruit of the gaoler's conversion; he brings the apostles, who were the instruments of his conversion, into his house; and having washed their stripes, refreshes their bowels: he set meat before them. The truth of conversion will manifest itself in a thankfulness, and other tokens of respect, towards those whom God has made the instruments of our conversion. True conversion changes men's thoughts of God's ministers, and causes men to love and honour those whom before they did disdain and scorn, persecute and hate.

Observe, 2. How full of joy and spiritual rejoicing this new convert was: he rejoiced. O the sweet fruit of faith in Christ! namely, peace with God, and joy in the Holy Ghost. Conversion always puts men into a joyful state: rejoicing, spiritual rejoicing, is the portion, the proper portion, and the peculiar portion, of converted persons: as it is sometimes their present portion. The gaoler, upon his believing in God, instantly rejoiced.