What does John 4:29 mean?

Some commentators note that a woman who had five prior husbands, and was living in sin (John 4:17), might well have been "connected" to many other men in town. In its own way, this might have been part of the motivation for some men to come and speak to Jesus (John 4:39). When she said Jesus knew everything in her past, it could have made some of the Samaritan men nervous. The Scripture itself doesn't specify. Regardless of motivation, the response to this woman's witness is impressive. The next few verses will describe many people meeting Jesus, and a door being opened for more evangelism.

Yet again, this Samaritan woman shows her shrewd and clever mind. In Jesus' day, women were considered unreliable witnesses. Fair or not, the Samaritan woman knew that if she made any overt claims about Jesus, they'd be dismissed. In that culture, nobody would trust the word of a woman. So, just as she used clever tactics with Jesus (John 4:11, 15, 19–20), she uses them on the people of town.

The way she asks her question, "Can this be the Christ?" is intended to be given a negative answer. She might have said it as, "This isn't the Messiah, is He?" By referring to Jesus' amazing knowledge, and suggesting the idea of the Promised One, she sparks curiosity. As a result, she brings many people to Christ, both physically (John 4:35), and in terms of introducing them to their Savior (John 4:39–42).