I haven't been in this situation since I left Islam but if I was, I would reply normally with شكر الله سعيكم. But it doesn't mean anything to me, it's just the (casual) way to reply certain phrases.
For example when someone asks me to do something in such a way (Will you inshallah finish it tomorrow?) I reply sometimes saying (inshallah). Again just as a part of the casual language. But of course I rarely use any phrase like that comparing to the time when I had been Muslim.

Islam has copied a lot from Christianity and Judaism as it did by adopting many Pagan practices (Like Hajj) after adding some Islamic touches. That's a known practice by the Abrahamic religions (and of course any other religion) to build on the already existing faiths which not only saves the time of the founder of the religion but also makes it easier for the local population to accept the new faith since it has many similarities with their ideologies.
If you read more you can easily find many similarities between the Abrahamic religions and the much older Zoroastrianism which was apparently the main source that offered the basis (especially in terms of the mythologies and fairy tales) for the Later religions in the Middle East.
A similar example in the Western world can be found between the Older Greek and the newer Roman Faith (Mythology).
You even find traces of Pagan practices in the Christian European communities, like the First of May celebrations in Germany where they raise the (Maibaum) (May Tree)... etc

Islam has copied a lot from Christianity and Judaism in addition to adopting many Pagan practices (Like Hajj) after adding some Islamic touches. That's a known practice by the Abrahamic religions (and of course any other religion) to build on the already existing faiths which not only saves the time of the founder of the religion but also makes it easier for the local population to accept the new faith since it has many similarities with their ideologies.
If you read more you can easily find many similarities between the Abrahamic religions and the much older Zoroastrianism which was apparently the main source that offered the basis (especially in terms of the mythologies and fairy tales) for the Later religions in the Middle East.
A similar example in the Western world can be found between the Older Greek and the newer Roman Faith (Mythology).
You even find traces of Pagan practices in the Christian European communities, like the First of May celebrations in Germany where they raise the (Maibaum) (May Tree)... etc

البقية بحياتك
A traditional condolence phrase used in Levant and Egypt. has no religious meaning and translated roughly to (you have the rest of life) or (The rest of life is yours) etc... Which means you still have the rest of your life to live

Oldest habitable city and Falafel

Unser Weg ist noch nicht zu Ende

So kick me the way that you would... If we die tonight

I'm Allah

Share the joint with her

Kiss while running

Run for my life!!!
To her

If you could read my mind

We could have been so good together

Her big... Heart

Grace

I want to Freak Bree

I'm a good guy

Take Brian for a walk in the nearby desert

Frida Kahlo

Flashbang