The scripture you cite is found at: (1 Corinthians 15:58)"Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your toil is not in vain in the Lord." (NASB)
1. We have the example of Cornelius, the first gentile to accept Christianity. His GOOD works were not in vain....God saw his fine works and rewarded him with the opportunity to become a follower of his son, Jesus. (Acts 10:1-4)
2. Mary (mother of Jesus) had a FINE reputation and was considered a 'highly favored one', and was given the honor and responsibility to bear and raise the Messiah.(Luke 1:26-31)
3. Dorcas was known for her kindnesses to others and faith in God, and was rewarded with resurrection (Acts 9:36-41)
None of this work was in vain because it was in harmony with God's will.
Matthew 15:7-9 indicates that SOME forms of worship ARE in vain
The destruction of Babylon the Great shows that BAD behavior is ALSO seen, taken note of and repaid.(Revelation 18:5)
Ecclesiastes 12:13, 14 indicates that God will bring EVERY sort of work into judgment. He doesn't miss a thing, so whatever we do in harmony with God's will, is NOT in vain...is not USELESS...it IS seen and remembered by God.
In vain is means not effective, useless For an example: His discussion about changing the uniform is in vain
Well...You just need to know what vain means.'It is vain to do with more what can be done with fewer.'or'My sister is so vain that she talks to herself in the mirror.'or'Some people are vain enough to laugh at ugly people.'
There is no such thing as being popular, and unpopular If your "popular" , Your Vain ( Vain=Think You Are Popular And Everyone Likes You)
Except the LORD build the house, they labour in vain that build it: except the LORD keep the city, the watchman waketh but in vain.
Indentured servants were forced into slave-like labor as a result of vain pursuit of a better life.
The adverb of the word "vain" is vainly.An example sentence is: "she vainly checks her hair again".
The vain young lady was late to the funeral due to not being able to decide what to wear.
She spent hours in front of the mirror, preening and admiring her reflection, showing how vain she was.
being very vain and bossy
You're so Vain.
Chaucer suggests the Pardoner is vain by describing him as being without a hood or hat, exposing his long, flowing hair that he believes makes him look more attractive. This detail highlights the Pardoner's preoccupation with his appearance and vanity.
The character is renown for his being zany , vain and greedy .