Hello Pilgrim,

Erskine's statement has everything to do with original sin, I am familiar with the Reformed church and RCC definition. His statement is not a doctrinal statement, that even the most innocent child is a viper by nature, with "the venom of the serpent", rather it is a statement by Erskine, nor is it the Gospel.

Regarding the entire writ and logic of Erskine...
The Lord Jesus had many things to say about innocent children; how lest we become like one of them, one cannot enter the kingdom of heaven. I know I am pulling out one statement, but at least that statement is from the Savior himself.