What my Father has given me is greater than all else, and no one can snatch it out of the Father’s hand. The Father and I are one.”
The readers of John’s gospel felt that they faced an uncertain future. In the 70 years between Jesus’ death and its distribution many things had changed for Jesus’ followers. With 2 or perhaps 3 generations of new followers they were no longer Jews but found they were becoming something else. And that “something else” wasn’t always clear for them. There were so many different expressions and ideas of who Jesus was and is that at times everything would have seemed to be up in the air.
So John seeks to reassure them by reminding them of Jesus’s words. God’s love and kindness is greater than human confusion. Nothing can ever snatch them away from God’s love in Jesus.