Passage
When he has put forth all his own, he goes before them, and the sheep follow him, because they know his voice.
John 10:4 (DBY)
Nearby Context
John 10:2 but he that enters in by the door is [the] shepherd of the sheep.
John 10:3 To him the porter opens; and the sheep hear his voice; and he calls his own sheep by name, and leads them out.
John 10:4 When he has put forth all his own, he goes before them, and the sheep follow him, because they know his voice.
John 10:5 But they will not follow a stranger, but will flee from him, because they know not the voice of strangers.
John 10:6 This allegory spoke Jesus to them, but they did not know what it was [of] which he spoke to them.
Study Lenses
The verse centers on "sheep", "forth", "goes", "before", "follow", and "voice". It is saying that the verse draws attention to "sheep" and "forth", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 3's "To him the porter opens and the..." into verse 5's "But they will not follow a stranger...", so "sheep" and "forth" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "sheep" and "forth" with trust shaped by these words, not by a vague optimism outside the passage.