This issue has been covered several times here. Malone's book has also been shown to be slightly incorrect in certain issues. Perhaps these threads could help shed light on the situation:

What is Credible Profession
Covers part of the problem with what to accept as a credible profession and how we cannot know who is elect and use this as a requirement for baptism.

Who departed
Covered the historical dilemma for all baptists; there are none until the 1600's and the early church was paedobaptistic.

Household Baptisms
Covers the problem of the meaning of household when applying it to baptism.

Visible / Invisible Church distinction
Covers the visible/invisible Church understanding and why election cannot be used as criteria for baptism.

Continuity
Covers the continuity issue. Most see more, Baptists see less.

OIKOS
Explains the scriptural meaning of household and how this shows continuity in administration in the NT.

I hope those help.


God bless,

william