What then, as Christians, are we supposed to be doing? What is our purpose in life? Surely it is to DO HIS WILL. [thy will be done on earth, as it is in heaven]
So we ask, how do we know what his will is? The answer to that lies in the matter of ‘doing coming out of being’. If we exhibit “the fruit of the Spirit”, then we are already “doing his will”, because his will is that we should firstly have his nature, and then exhibit, reveal, his nature to the world. But the second part of that, is that ‘doing arises out of being’, in that the Spirit reveals “his” will, which is that, being love, love loves. So being of the love nature, means we love. And loving is a doing, just as it is a “being”.
God loves because he is God, and God is love. We love because [he first loved us] we know his love and have internalised it (Him).
So the simple answer to “What is his will”, is that his will is for us to “be filled with the Spirit”.
If we were to start talking about being obedient, which is fair enough, and then we could say something like “Well Paul’s will was powerless in Romans 7, until he moved into chapter 8, and found the Spirit” [of Christ]. And then he “found” his will again. [hypothetical]
But now as those who “have found the Spirit”, if we are to “follow the leading of the Spirit”, then we must, in obedience, submit our will to his, in the form of following where he leads, and while we are following, being obedient to that which he reveals in the process. [his spirit IS his will]
So to follow the Spirit we must first have the Spirit, which as Christians we already do, and to maintain the “following”, we must maintain the “filling”.
So to say it again, God’s will is for us to be filled with his Spirit. [as a Christian, to maintain the fulness of the indwelling Spirit] [There is a verse “..and then you will know his good and perfect will…” Romans 12 – 1,2.]
[ also parable of the wise virgins, keeping the lamps filled.]
later edit (PS There is also a case for “being” emerging from “doing”, eg as in the case of “as they went, they were healed”. So as we obey his will, it becomes a part of us.[it becomes complete, or completed, in us, and through us.] This does not alter the case for the above.) (And ‘following the leading of the Spirit’ could also indicate simultaneous submission and obedience).(and being ‘in the Spirit’, a composite of all this.)(and by internalising his love, we are internalising his will).