Baptism, the Church, and Apostasy

Here begins a series on baptism, it's function in the church, and apostasy. Don't see the correlation? Stick with me, I think you will. All of this is flowing out of my study on the believers union with Christ (which has been faith changing!), a study I've been doing amidst increasing conviction that us evangelicals lack a robust doctrine of the church.

Like most series I start, it's for me - I get more clarity as I write. On this, I am really looking for dialogue partners. Some of my convictions are shared widely by other Reformed writers. Other don't seem to be. TI feel like I'm out on a limb by my lonesome. Maybe for reason, so I invite push back.

Here's a basic outline:
1. The church can be talked about in terms of the invisible church and the visible church, or the church militant and the church triumphant. Both are helpful. As evangelicals, I think we way overemphasize the invisible church and way underemphasize the visible church. Not sure we even think about the difference between the church militant and the church triumphant.

2. Membership in the church invisible (and triumphant) is based on God's eternal decree. The number of this church cannot be added to or diminished by a single person. But what is the basis for membership in the church visible, the church militant? I believe it's baptism. It is by our baptism that we are grafted into the church and become members of the covenant community. As circumcision was the initiatory rite that introduced children into the covenant community of Israel, so baptism marks the entrance of people into the new covenant community called the church.

3. This understanding goes a long way in helping me understand the warnings against apostasy in the book of Hebrews, and elsewhere. I don't believe it's just a hypothetical situation. Nor do I think we should say they weren't real Christians. Baptism is what identifies someone as a Christian in the objective sense - the baptized takes the name of Christ in their baptism, being baptized in his name and in the name of the covenant God: Father, Son and Holy Spirit. This does not mean that they were a part of the elect and lost their election. That is impossible. But they were a part of the visible church, a part of the church militant. They were a part of the new covenant community and party to the terms - faith brings blessing, unfaithfulness brings curse.  They are unfaithful to the terms of the covenant, but they are at least under the terms of the covenant (as opposed to those who bear no mark of the covenant and live outside of it).

Ok, I know I've bitten off more than I can chew on that. I'll be posting on each soon.