Acts 8:4

Samson's riddle is here again unriddled: Out of the eater comes forth meat, and out of the strong sweetness. The persecution that was designed to extirpate the church was by the overruling providence of God made an occasion of the enlargement of it. Christ had said, I am come to send fire on the earth; and they thought, by scattering those who were kindled with that fire, to have put it out, but instead of this they did but help to spread it. I. Here is a general account of what was done by them all (Act 8:4): They went every where, preaching the word. They did not go to hide themselves for fear of suffering, no, nor to show themselves as proud of their sufferings; but they went up and down to scatter the knowledge of Christ in every place where they were scattered. They went every where, into the way of the Gentiles, and the cities of the Samaritans, which before they were forbidden to go into, Mat 10:5. They did not keep together in a body, though this might have been a strength to them; but they scattered into all parts, not to take their ease, but to find out work. They went evangelizing the world, preaching the word of the gospel; it was this which filled them, and which they endeavoured to fill the country with, those of them that were preachers in their preaching, and others in their common converse.

— Matthew Henry's Concise Commentary (public domain)

they that were scattered abroad went everywhere preaching--Though solemnly enjoined to do this (Luk 24:47; Act 1:8), they would probably have lingered at Jerusalem, but for this besom of persecution which swept them out. How often has the rage of Christ's enemies thus "turned out rather unto the furtherance of the Gospel" (see Phi 1:12-13).

— Jamieson-Fausset-Brown Commentary (public domain)