great & least

This is Jesus speaking here, talking to his disciples...

Matthew 19 

29 And everyone who has given up houses 

or brothers 

or sisters 

or father 

or mother 

or children 

or property, 

for my sake, 

will receive a hundred times as much in return 

and will inherit eternal life. 

30 But many who are the greatest now 

will be least important then, 

and those who seem least important now 

will be the greatest then.

So, what does all this mean in reality for each of us?