In yesterday's daily bread (Joshua 19) towards the end of his life Joshua said to his audience, "You are NOT able to serve the Lord."
This statement bothers the reader because according to the scripture we are called to (worship God and) serve him (only).
It is given that God does not (and cannot and should not) ask man to do what he is NOT capable of doing.
Why then did Joshua says, "You are not able"?
Was it because the flock before him were indeed not able?
In view of joshua's wish and prayer to bless them, the answer to this question is yes and no:
(1) Yes because as they were they were indeed unable for like stone or donkey they are created beings not the creators so there is a limit to what they can do and serving God is one of the things that they could not do. You are a human being and you cannot travel from earth to moon on foot! Worshiping and serving God is one of the examples that they could not do on their own!
(2) No because as the Scripture says that which is not possible with man is possible with God. NOTHING is impossible with God so as the apostle paul says I say "I can do everything through him who gives me strength" and "I live by his faith (in Him)."
Joshua might have said this so the flock would know their limit so they would humble repent (of the so called my own man mentality) surrender/turn to the Lord and serve him by faith in him and LIVE!