Read his three-piece concerns on the subject:
I will say this as follow-up to Derek's concerns, oriented through my own lens, which tends to orient ecclesiological and ascetical concerns to the Person and work of Jesus Christ:
Jesus Christ's incorporation of us into His own Body, not simply inclusion into any old community--the Church is not a club (and parties left and right be ware! Unsavory ones, Gentiles abound.), is for me the explicit theological point of entry for God's wide welcome, into explicit relationship within God's own Life, made available at the Font by water and word and the Holy Spirit.
Explicit Welcome into and living within God's own Life is through God's Community, the Church, we are given a Community and given over to one another in Christ, which should signify to us and to the whole cosmos, that God's Welcome explicitly received and taken up and put on in Holy Baptism, and living in as well as out of God's own Life as flesh and blood human creatures, works itself out on the level of creatures in the ways we relate to one another and the whole cosmos in Christlike ways and not (and when not, turning again and again, to our only Life). St. Paul calls these fruits of the Spirit: faithfulness, promise-keeping, courage, listening (obedience), and the like.
In other words, God's Welcome explicitly received and taken up and put on in Holy Baptism and living in God's own Life flows into discipleship rooted first and foremost not in being the interlocutor of my sister or brother, but of myself. How might my habits, emotions, attitudes, behaviors not show forth God's love of myself, my neighbors, and the whole cosmos? Where do I lie? Not keep a promise? Forget the least? Scorn the vulnerable?
Where we downplay that our Baptism is an incorporation into the Life of God the Father Unbegotten through Jesus Christ the Son Only-Begotten by the Holy Spirit Proceeding in Christ's Community, that is, Christ's Body, Christ's Temple, Christ's People, Christ's Convocation, Christ's Church, Christ's Bride, Christ's Friends, we fail to be honest of Whose we are as members and of our calling when inviting the potential praiser, and so, we fail to be the Church, the visible Witness to God in Christ.
God's Baptismal Covenant presupposes this grounding as the inclusion into Christ's Community, beginning as it does with The Apostles' Creed, and only then moving on to our promises as response. It also suggests that inclusion in this Community, Christ's very Body, requires of all of us as response the ongoing reordering of the way we relate to one another, the world, and creation--that is, discipleship, in light of Who Christ is for us and to us. The fallout of being incorporated by God through God's Community is a life ongoingly reordered to the Incarnation in His totality, namely, His Person, Jesus Christ, is a life, in other words, reordered to the Life of the Holy Trinity on the level of human creatures.
In the totality of Incarnation of the Second Person the Word the Only-Begotten from Conception to Cross, from Resurrection to Ascension, heaven and earth are irrevocably joined. This is the bedrock and ground of our witness, our proclamation, our invitation. And it by this lens that we are called to live in all the everyday and ordinary as well as the extraordinary difficulties of being alive.
We need not be anxious mongerers of damnation, swelling the ranks of the Font through fear and unbelief, nor need we be hawkers of salvific wares as if the chief point were purchase of heaven rather than receiving Life in God, but we are called to witness, proclaim, point to, and invite all peoples and indeed the entire cosmos into open praise-response to this Generous, Loving, Saving Word Who Has Once-For-All Overcome, Who is present and working among us hiddenly in the day-to-day life of the world and all of creation, and Who is present to us explicitly wherever two or three are gathered in His Name in Psalm and Prayer, Word and Sacrament, in proclamation as well as presentation.
We are called as the Witnessing, Praise Community to invite all so moved to receive and take up their part and put on Christ in the Witnessing, Praise Community, and Holy Baptism is the means given us for this purpose as well as the chief visible witness and Testament in matter and by word to the work of God's Holy Spirit in making known God's irrevocable decision for me, for you, for us, for the whole cosmos in Christ Jesus once-for-all.
Giving no explicit account of Who we receive in Holy Communion and the claims this One makes on us to grow up into full stature, is false advertisement of a chummy hospitality cheese-and-cracker affair without the risks entailed in receiving God's xenia, God's peace-offering. God's xenia, God's peace-offering will and does change us, and starts not with that one or that one, but with pointing at me in making self-examination, of reflecting on where my own life shines forth less than God's once-for-all peace wrought fleshwise in Christ.
If and only if we are clear and upfront that it is this Life Who we are inviting any and all to receive at the Altar-Table, then should we feel comfortable opening up the Altar-Table without explicit mention of Holy Baptism as prior ground.
And with this warning to us should we so choose: We set up the one unbaptized receiving for great travail, for she or he has no visible Mark by water and word so necessary to a created race, that Irrevocable Sign and Seal of God's joining heaven and earth once-for-all in Christ.
She or he has no explicit being joined to the Support Community by etching on her or his flesh by drops and drips and splashes of water with words of God's Irrevocable Embrace sealed by oiled traces crossward forever, of which our daily remembrance by marking ourselves (+) at The Apostles' Creed serves as rebuke to hell, and upon which we fall back when the Tempter comes scheming, and the Tempter will come as F. D. Maurice reminds us: Baptismal Calling
Here are some of my previous posts that relate to the matter: