Who can be called Jesus' flock? Is there anything one can do to remove themselves from the hand of God?
Chapter 10 comes "off the heels" of chapter 9's discussion of the standard by which one knows whether or not they are following God--whether they *see* Him (if they even can) and what it would look like to walk in His footsteps. To describe this, Christ uses two metaphors to describe Himself: he says he is simultaneously the "gate" (John 10:9) and the "good shepherd" (John 10:11). Jesus says that He leads His flock through the gate, and that His sheep know his voice, and run from any voices that are not His. When beginning to speak of laying down His life for His sheep, the Jews around him question again as to whether or not He is possessed.
There seems to be a clear shift toward a descriptive tone beginning in John 10:22. Here, the Scripture mentions that Jesus celebrated Hanukkah--He was, of course, a Jew. Let's take a quick look into the history of Hanukkah (also spelled Chanukah).
The Story of Hannukah (detail), by Ori Sherman 1985. Credit: Magnes Collection of Jewish Art, UC Berkeley
THE FOLLOWING IS AN EXCERPT FROM THE TORAH.COM (https://www.thetorah.com/article/the-original-meaning-of-chanukah)
"Chanukah was first celebrated in 164 BCE as a ritual festival in which the Temple was purified and special sacrifices were offered (after it was desecrated by the Seleucid king Antiochus IV Epiphanes). The Maccabees dedicated the defiled Temple for eight days; it is therefore referred to as “the days of the dedication of the altar” (1 Macc 4:48; Hebrew, חנוכת המזבח)."
"They also repaired the sanctuary and the interior of the temple and consecrated the courts." 1 Maccabees 4:48
"Judah and his men purified the Temple, built a new altar, consecrated it, and prepared new sacred vessels; they prepared new incense, lit the lamps in the lampstand Menorah, placed the showbread on the table, and rededicated the altar with numerous sacrifices, singing, and prayer. 1 Maccabees explicitly states that the dedication of the altar lasted eight days and that Judah and his men declared that every year the eight days should be observed as a festival, beginning on the 25th day of Kislev (1 Macc 4:41-48)."
James Tissot (Nantes, France, 1836–1902, Chenecey–Buillon, France). Jesus Walks in the Portico of Solomon (Jésus se promène dans le portique de Salomon), 1886–1896.
Jesus begins walking around the Portico of Solomon and some of the disciples ask Him to clearly label Himself as Messiah. He says that He has done deeds to testify to that fact, and that the sheep know. If one is among the sheep, they will know Him. Then He speaks a powerful line about the inability for others to rip a sheep out of His hand:
"I give them eternal life, and they shall never perish. No one can take them out of my hand. My Father, who has given them to me, is greater than all, and no one can take them out of the Father’s hand." (John 10:28-29)
A Christian doctrine has arisen fairly recently known colloquially as "once saved always saved" that argues that there is nothing one could do to lose their salvation, partly utilizing this verse as justification. In response, many (including Catholics) argue that the passage maintains the possibility of oneself "removing" themself from God's hand--this seems to jive with further verses in John 15 where Christ asks his followers to remain in His love. Does this make sense if not even oneself can be removed from God's hand?
Jesus then says that the "Father and I are one" (John 10:30) which seems to put Him on the level of God the Father. For this, the Jews around Him believe He has spoken a great blasphemy. Jesus replies that they would be right to think it blasphemy, that is, if God was not clearly working through Him. They try to arrest Jesus, who flees to the Jordan. Many begin to believe when they realize John the Baptist spoke truths about Christ though he himself did not perform miracles.