In their relationship with Everyman, the characters differ as they promised not to follow Everyman to the grave while the others refused.
'Everyman' represents to every-man in the world. It's a morality play that was written anonymously. The play reveals what happens to a man when he goes down to the grave. The protagonist, Everyman recieves an announcement about his death, then he goes to asks his friends to accompany him to his grave. His friends called Kindred, Fellowship, Beauty, Cousin, Goods, Strength, etc all deserted him when they knew he was going to die. These were people he called his true friends.
But Good Deeds, Knowledge, etc agreed to go with Everyman to the grave. So when others left, Good Deeds was left behind with him.
Therefore, these characters differ from Everyman's "fair-weather" friends because they agreed to accompany him to the grave while the "fair-weather" friends refused. Fair-weather friends are only friends in the good times but desert one in the bad time.
The characters differ in the relationship with Everyman as they promise not to forsake Everyman to the grave.
Everyman is a morality play written anonymously. The play's protagonist is 'Everyman' that represents an average man or every-man in the world.
The play is about what goes with a man to the grave. The play starts with an announcement that Everyman, the protagonist, is going to die. Then the protagonist goes to his friends to ask them to accompany him to his grave. But the friends whom he called as his true friends, Fellowship, Kindred, Cousin, Goods, Beauty, Strength, etc all left him as soon as they knew that Everyman is going to die.
But, when the fair-weather friends denied accompanying Everyman to his grave, Good Deeds, Knowledge, Confession, etc agreed to accompany him to his grave. When Everyman was put in the grave, the only friend left with Everyman was Good Deeds.
So, the difference between the fair-weather friends and other friends in the play is that the former ones denied to accompany him whereas later ones agreed.