Jehovah's Witnesses and other Christians, can you please explain this verse to me?

Paul was contrasting Christ with Adam. (1 Corinthians 15:45-49) Adam, the first man, “became a living soul.” (Genesis 2:7) “The last Adam”—Jesus—“became a life-giving spirit.” He gave his life as a ransom sacrifice, first in behalf of his anointed followers. (Mark 10:45) As humans, they ‘bear the image of the one made of dust,’ but when resurrected they become like the last Adam. Of course, Jesus’ sacrifice will benefit all obedient mankind, including those resurrected on the earth.—1 John 2:1, 2.