Join the choir embracing church leaders every Monday planning in secret (8)
I believe the answer is:
scheming
'planning in secret' is the definition.
'scheming' can be an answer for 'planning' (scheming is a kind of planning). I am unsure of the 'in secret' bit.
'join the choir embracing church leaders every monday' is the wordplay.
'join the choir' becomes 'sing' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'embracing' indicates putting letters inside.
'church' becomes 'ch' (common abbreviation).
'leaders' says to take the initial letters.
The first letters of 'every monday' is 'em'.
'ch'+'em'='chem'
'sing' going around 'chem' is 'SCHEMING'.
Can you help me to learn more?
(Other definitions for scheming that I've seen before include "Devious" , "Duplicitous" , "Plotting secretly" , "far from 10 [WIDE EYED]" , "cunning" .)