Jacob summoned his sons and blessed each one in accordance with his unique contribution to the overall Divine mission of the Jewish people. These became the defining characteristics of the 12 tribes that descended from them.
Jacob gave them all the blessings that he gave each one individually.
Although we each have our own unique roles in our Divine mission to make this world into G-d's home, we are all involved to some extent in the roles played by others, as well. There are three increasingly effective ways that we can do this:
We all focus exclusively on our personal tasks, but since we are working toward the same goal, we all share in the results of our separate accomplishments.
We invite and encourage one another to participate occasionally in the personal activity that we emphasize.
When we periodically engage in tasks other then our forte, we immerse ourselves in them just as fully as we do when we engage in our personal task.
Participating in each other's endeavors fosters Jewish unity, making us worthy of G-d's blessings, including -- and especially -- the ultimate blessing, the Messianic redemption.