Did Jesus die in vain if not everyone is saved?

He did not die in vain. God promised that everyone who puts their trust in what He accomplished would be His for all eternity. Though not as many as some expect will be saved, the multitude of believers belongs to Him, and no one can take them from Him.

Les teaches that God made the promise that every believer would be His for all eternity, so Christ did not die in vain. The context contrasts Ishmael and Isaac: Ishmael's physical offspring became numerous—the Arab world outnumbers the Jews 50 to 1—but the children of promise are believers. Les explains that God will not get near as many as we might think He should, yet the multitude who have become believers are His, and no one can ever take them from Him.

Did Jesus die in vain if fewer people are saved than we expect?

No, Jesus did not die in vain. Although the number of saved people will be fewer than many expect, every believer is His for eternity. The multitude who have become believers belong to Him, and no one can ever take them from Him. His death accomplished its purpose.