Passage
But many of them who had heard the word believed: and the number of the men was made five thousand.
But many of them who had heard the word believed: and the number of the men was made five thousand.
Acts 4:2 Being grieved that they taught the people and preached in Jesus the resurrection from the dead:
Acts 4:3 And they laid hands upon them and put them in hold till the next day: for it was now evening.
Acts 4:4 But many of them who had heard the word believed: and the number of the men was made five thousand.
Acts 4:5 And it came to pass on the morrow, that their princes and ancients and scribes were gathered together in Jerusalem.
Acts 4:6 And Annas the high priest and Caiphas and John and Alexander: and as many as were of the kindred of the high priest.
The verse centers on "heard", "word", "believed", "number", "five", and "thousand". It is saying that the verse draws attention to "heard" and "word", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 3's "And they laid hands upon them and..." into verse 5's "And it came to pass on the...", so "heard" and "word" belong inside that flow. In Acts context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "heard" and "word" with trust shaped by these words, not by a vague optimism outside the passage.