Responses to some resent questions:
What is the nature of the church?
The church. I was obsessed with this concept when I first became a Christian (1972). The contrast between what the book of Acts and the Epistles talked about and what I saw in "churches" was amazing. I began reading early church history (FF Bruce, The Spreading Flame) and material on "house churches." I also began to think of the church from the perspective of the continuance of the OT Covenant community of faith. It was "to Israel" that the Messiah had come. It was to fulfill the covenant and the Lordship of God over his people that Jesus in Kingdom language was to inaugurate. St Paul had said that "through the Church, the manifold wisdom of God" would be made known. Hence the Church is the "alternative" community of God's People through which the Spirit moves to create a people who, by their lives of love, compassion, service, grace and forgiveness, will demonstrate how God created us to live with each other. It is a community life of dependence on Jesus teaching and the work of the Spirit. It is a free community of trust, vulnerability, and hope for the future.
Also, the book "The Misunderstanding of the Church" by Emil Brunner is profound. But for so many who have been raised accepting the institutional church process, polity, governance, and control this is a hard read.
Who are God's people?
The question about "who God's people are?" is an interesting one. I have two approaches. 1) Theologically, there are no people of God. God's No, which becomes God's Yes, since Yes was actually the First word, before No.(Barth) That is, the judgement against disobedience is comprehensive (Gen 6:5). Yet, the grace of God has determined to "re"create a people for himself. In the same way that Cain forfeited his relationship and "another son" came to play as the "imago dei" so God continues to create "out of nothing" a people for himself. All the barren women in the OT and Mary in the new stand as part of the "nothingness / barrenness" out of which God creates. That is, Israel, a People of God, does not exist as an "historical evolution of culture." Israel, and the larger growth of a People of God, are not some dimension of natural anthropological, ethnic, or cultural processes. Their existence is "in" the Messiah. As with the Church, it knows no cultural or religious identity out of which it comes. It is by being "in Christ" that the Church and therefore a person is "adopted" and is now a member of the Body of Christ. The Death and Resurrection (i.e.Baptism) for believers is their "creation out of nothing" and therefore they now exist not naturally but by the power of the Spirit. 2) Sociologically (Bonhoeffer), the Communion of Saints exists within society as a free people, called to witness to the work of God in the Word as Christ. Christ and Church are merged in the Witness of the Spirit to present to the World an alternative "kingdom." From decisions of community life to ministry in society, all aspects of this fellowship are about "being Christ in the world." When the church adopts societal structures it loses its ability to both judge and save. It is present when and where the serviceability of kingdom characteristics are lived through the Spirit.
How do we love as a ministry?
As for Love, isn't it by nature a ministry in itself, that is as an event. Since love is an activity and not a feeling (per se), it is engaging, embracing, and evoking. It is responsive to the context of the "other" and always pulls from a source which is beyond the one loving. It seeks, discovers, and then incarnates itself into a form which identifies with and honors the ones in the context it enters. Anderson used to say, "Love is the intensification of the other." That is the core and nature of ministry, a service to another for their sake and the sake of the source of true love.
How does the HS inform us as to our authority, power and service?
"How does the HS inform us..." is an interesting question. In one sense, we might compare it with how do we know anything? One thing I have learned from Barth, Torrance, and Anderson, and Michael Polanyi, is that for knowledge to be true, that is, creating a consistency of source and target, between that which is "outside" of us, and that which we call our "knowing it," we must conform our "knowing" (our methodology of knowing) to the nature of the object to be known. That is, we cannot simply apply any methodology of investigation and knowing, to any object and expect a consistency of reality to experience of it. Some things need to be known along the lines of dissection, or logic, or interpersonal communication. Some things are worked out mathematically, others are known through engagement and reciprocity of trust. The assumption is that not all knowing happens in the same way. Our Modernist history suggests that empirical knowledge is the only thing trustworthy (interesting that trust is a validation of empiricism!). Yet, more physics suggest that engagement with reality changes it, and therefore commitment and dynamic engagement are necessary components to sufficiency in knowledge. Heb 11:1 and its comment about "Faith is the conviction of things unseen" is interesting in that faith and conviction are held in union. St Paul talk about "knowing in whom I have believed." What is the relationship between knowledge and faith. I God desires us to know him through faith, could faith be the actual epistomological form of knowing commensurate with the object to be known, in this case, God. Actual knowledge of God is only possible through faith, since God gives Godself to be known only in faith. "If you believe with your whole heart...." The assurance of faith is not about faith, per se, but the object to be know by faith, and that object (God) actually, truly and seriously "giving" Godself to be known in the act of our faith. In Ezekiel, the key refrain is "that they may know I am the Lord." God actually, and quite literally wants to be known, but known in a way consistent with Love, that is relationally, through trust, commitment, engagement, compassion, forgiveness, etc. These are forms of knowing through commitments of faith in the "other." We can now talk about how the HS allows us to know things. Since the HS is the Spirit of Jesus, and we have come to know Jesus in faith and by engagement with His Word, the paradigm of that relationship is set, we can "test" the Spirit relationally through consistency with the Word. We can judge the Spirit through the Spirit's consistency with Jesus in the Scriptures. We will know the work of the Spirit in us for service and ministry by the fruit of the Spirit, which is the outcome of a relationship of love, in freedom and service. This is all done with freedom to explore, probe and move out, believing that the Spirit is with us to guide and direct us. It touches our "spirit" in ways consistent with our sensitivity to its work (like a sheep and the shephers voice or the hand of a parent on the shoulder) in our lives. We learn sensitivity and discernment through the years of experience "in the relationship." Paul calls this growing in the "maturity of Christ." It is all founded on the commitment to engage over time with the One who has called us to service.
How do we engage with culture without seeing ourselves as a part of it?
As to culture and our part in it (nor staying apart from it), we are interwoven into culture. We are born into a culture in the same way that Jesus was. We learned to speak a language, eat food, dress, tell stories, and enagage socially just like Jesus did. Jesus, from a distance could have been confused with any other man of his age and social makeup. I was born in Hollywood, Ca. I grew up in LA, surfer, love mexican food, have long hair and play guitar. 90% of that is still true. Becoming a Christian changed some of that, but not all. Jesus's stories about vineyards culled local lore and culture and turned them into Word of God. All culture can be used that way. Jesus turned the lives of sick people into the Word of God. Jesus turned stories of tax collectors into the Word of God. Jesus turned the encounter with a "woman of the well," a cultural outcast into the Word of God. So who has more power, culture of Jesus. The key to not "being a part of it" is to always know that culture too is in need of redemption. Not so that long hair becomes short or that jeans becomes slack or that dark dress shoes become Converse, but that it does not determine who we are before God. St Paul says that he became all things (and I think he meant something like "religious") in order to relat to all persons. Jesus was viewed as a "glutton and a wine bibber" (KJV :) ) because he did not see "what he was doing" as a conflict with whom he was engaging to love and care for. You become lost to culture when you act in ways which go against justice, peace, the care for the poor and the widows, or others who are treated improperly by the impersonalness of culture. You become lost in culture when you allow the culture to tell you about Jesus, rather than the other way around. Jesus teaches us about culture, it is relative. I am free in every respect to culture, but not to become a slave to any dimension of culture. The incarnation is God taking culture up into Himself and saying "breath on these dry bones and they will live again." In one sense when the "Word became flesh and lived among us, but the world did not know him..." it was because he looked, on the surface, too much like the cultural world of his time. And culture can be very shallow. But he knew them.....