The word, "welfare" is found 20 times in the Book of Mormon. 7 of these is part of the expression, "welfare of your/their souls". There is also "your own eternal welfare", "welfare of Zion" and "welfare of the covenant people". The Book of Mormon is a frequent reminder to us of what is really "the desirable above all things" and "the most to the soul" (1 Nephi 11:22-23).
Another expression found 10 times in the Book of Mormon and nowhere in the Bible is "great worth". It is interesting to note the only time out of those 10 where this refers to something secular. It's in Alma 11:25 when Zeezrom is trying to trick Amulek into denying God by offering him "six onties, which are of great worth". Amulek doesn't fall for that because he knows of other things of greater worth that would be compromised if he denied God. The other 9 "great worth" expressions in the Book of Mormon refer the scriptures/prophecies/commandments/word of God or the marvelous work in the latter days
2 Nephi 2:30
And I have none other object save it be the everlasting of your souls.1 Nephi 8:37
And he did them then with all the feeling of a tender parent, that they would hearken to his words1 Nephi 15:25
Wherefore, I, Nephi, did exhort them to give unto the word of the Lord; yea, I did exhort them with all the energies of my soul, and with all the which I possessedEnos 1:9
I began to feel a for the of my brethren, the Nephites; wherefore, I did my whole soul unto God for them2 Nephi 1:16
And I desire that ye should remember to observe the and the judgments of the Lord; behold, this hath been the anxiety of my soul from the beginning.2 Nephi 33:3
But I, Nephi, have written what I have written, and I esteem it as of great , and especially unto my people. For I continually for them by day, and mine water my pillow by night, because of themMosiah 28:3
Now they were desirous that salvation should be declared to every creature, for they could not that any human should ; yea, even the very thoughts that any soul should endure torment did cause them to quake and ....and so on. We need to worry about the right things and the Book of Mormon reminds us what those are.