What does the nobleman's son's sickness say about Israel's spiritual condition?
The nobleman's son was sick and near death, not dead, and this pictures Israel's spiritual state at that time. Israel was not spiritually dead but was gravely sick, showing a nation in serious spiritual illness and needing healing. It illustrates that Israel was still alive spiritually but in desperate need of Christ's healing.
Les teaches that the nobleman's son is the second sign in John's Gospel. The son was sick, not dead, and was at the point of death, so the nobleman urgently asked Jesus to come down to Capernaum and heal him. Les then applies this directly to Israel's spiritual condition at that time: when he asks where Israel was spiritually, the answer is that they were sick. They were not dead, but oh, they were sick. This follows the first sign, where water turned to wine pictured the fullness of joy Christ would bring to Israel, and the disciples' faith was cemented by miracles.