Well, Penguin had a good stab at the meaning but was misled by Fuxflux, who should have given the source of the quote:

It comes the short story "The Regatta Mystery" by Agatha Christie:

Isaac Pointz and Leo Stein were Hatton Garden diamond merchants. Sir George and Lady Marroway came from a different world - the world of Antibes and Juan les Pins - of golf at St Jean de Luz - of bathing from the rocks at Madeira in the winter.

In outward seeming they were as the lilies that toiled not, neither did they spin. But perhaps this was not quite true. There are diverse ways of toiling and also of spinning.

I don't recall ever having seen the expression "in outward seeming" and can't find any explanations of its meaning. It sounds very dated. I read it as meaning "They gave the impression that they were like the lilies that toiled not, neither did they spin".

"Toil" means to work very hard and "spin" (in this context) means to spin thread.

So the whole sentence, rewritten in current English, means something like "They gave the impression that they didn't have to work".

I've never read anything by Christie and wonder if The Regatta Mystery is typical of her writing style. I find the phrasing and biblical reference very dated and would have thought it was much older than it actually is.

Ja, da wäre eine Quellenangabe natürlich sinnvoll gewesen. Der entscheidende Satz aus FernSchreibers Post ist dieser hier:

"Toil" means to work very hard and "spin" (in this context) means to spin thread.

Ich war auch eher an dem "in outward seeming" hängengeblieben und war gerade so weit, es als "outer appearance" zu verstehen, äußerer Anschein.

Die hier versammelte Gesellschaft erweckt also den Eindruck nicht arbeiten zu müssen, mit der Einschränkung, dass vielleicht ihre Arbeit nur nicht erkennbar ist, weil es halt viele verschiedene Arten zu arbeiten gibt.

Der genannte Abschnitt aus dem Anfangsteil der Bergpredigt, einer Pastiche aus höchstwahrscheinlich echten Predigten Jesu, gehört in den unterschiedlichen Versuchen einer Gliederung stets in einen Textzusammenhang, der erst mit Mt 6,34 endet:

Darum sorgt nicht für morgen, denn der morgige Tag wird für das Seine sorgen. Es ist genug, dass jeder Tag seine eigene Plage hat.

Durch das Zitat werden die vier hier skizzierten Personen als Menschen dargestellt, die nicht auf tägliche Erwerbs- oder gar Lohnarbeit angewiesen sind, eigentlich eine Persiflage auf die Bedeutung der zitierten biblischen Passage, aber dadurch doch gut charakterisiert.

Was mal wieder die Bedeutung von Textzusammenhang, auch Kontext genannt, und Quellenangaben belegt (und ich war ja schon stolz, die Bergpredigt erkannt zu haben!)

#7 Durch das Zitat werden die vier hier skizzierten Personen als Menschen dargestellt, die nicht auf tägliche Erwerbs- oder gar Lohnarbeit angewiesen sind,

No, I don't think it necessarily implies that all four didn't have to work, only Sir George and Lady Marroway (who) came from a different world. There's a clear contrast between them and the diamond merchants who, being merchants, presumably did have to work.

That is so good!

#4 I find the phrasing and biblical reference very dated. 

Well, a Bible quotation is a Bible quotation (and, as is usual, the form in which it's cited is based on the KJV -- Matthew rather than Luke -- they toil not, neither do they spin).

But phrases like "In outward seeming" and "diverse ways" do sound quite stilted and, I would say, not typical of Christie. Is there, perhaps, a narrator whose style this is supposed to be? I don't know this story.

#10 "(to) toil" war mir übrigens aus einem älteren Kontext bekannt. ...

Yes. There was also Churchill's famous "blood, toil, tears and sweat".

related discussion: they neither toil nor spin

Agatha Christie and the lilies (of the field) came up in another forum discussion, relating to a usage in Dead Man's Folly. She used it in other works as well. The metaphor of the "lilies of the field" for the idle rich is quite common in pre WWII literature, isn't it? I feel like I've read it several times. Most memorably in Wodehouse:

"Like the lilies of the field, they toiled not neither did they spin but lived quite contentedly on the paternal dole."

In outward seeming, to outward seeming... to me these expressions sound like "to all appearance", which is to say, they carry an unspoken "but" - The Marroways appear to be idle and thoughtless but a there is more there than meets the eye.

Stilted? Perhaps. Maybe just more old-fashioned language chosen to go with the Biblical "toiled not, neither"

#14 Like the lilies of the field, they toiled not neither did they spin but lived quite contentedly on the paternal dole.

Thank you, That is quite excellent. Better than the Christie. I must reread Wodehouse.