Everyone is at different stages of maturity you can't lump everyone into the same group but they can plant seeds they can water but that isn't anything, ultimately only God can give the increase
1 Corinthians 3
7 So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase.
8 Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour.
They are worth so much that he shed his blood and died for them, And God works in them however he wants for his own will and of his good pleasure, that's my point I wouldn't want to make that judgment because you don't know the heart
So for furthering his kingdom, Because they have become children of God and God lives in them they can express the love of God to a lost world, As God is Love we should try to reflect that love, as opposed to trying to decide who is saved or not based on works you witness