Not just as individuals but as a group of people, how do we listen to God?
I take your point and the difficulty of it. I for one cannot speak of 'hearing a voice from the blue', but I think there are various ways of listening to God. One is through his word. We need minds that are filled with it, so that God can use his word that is stored in our memories and his Holy Spirit can bring it to our minds. I think also that the Holy Spirit himself communicates with our spirits: 'The Spirit himself bears witness with our spirit that we are children of God' (Romans 8:16). If you ask me how it's done, I can't tell you, but Romans 8 affirms that the Holy Spirit witnesses with our spirits and has spiritual communication with us.
Another way that God speaks to us is through prophets. Please don't throw me out, I still believe that God has prophets. Not that you can go down the street and consult one as Saul did, and get an answer, but God does speak to us through our fellow members of the Body of Christ, and a word comes sometimes as a word to our hearts without their knowing it. I myself think it is important to observe what the Lord Jesus said before he went away, 'I will . . . manifest myself to [you]' (John 14:21). I take that literally but I don't think it means that we see visions and hear voices.
On the other hand, after the resurrection, before our Lord ascended to heaven, he spent forty days appearing to his own, and I think he gives us in those occasions literal examples of what he will do spiritually. To the two on the road to Emmaus, there came near a stranger. They didn't even know it was the Lord, but there was something about him as they talked about the Bible with him that moved their hearts very strongly. They discovered eventually that it had been the Lord. I think our Lord still does that. Not every day of the week, but there are times when he comes, and very often we recognize only when it's finished what has happened.
Similarly, with Mary. She didn't get a long theological exposition on the Bible. She loved the Saviour, and in the garden the Lord appeared to her and made her relationship with God so very real. And similarly, for those who were working in the boat, our Lord so interposed that when the miracle was over they realized it had been the Lord.
I think very often it is beyond our powers of explanation, when believers sense that God has spoken and they have had a very real approach of the Lord Jesus.
