Shallow believing falls short of consummated believing in Christ which results in salvation. Luke 8:13 - But the ones on the rock are those who, when they hear, receive the word with joy; and these have no root, who believe for a while and in time of temptation fall away.
In CONTRAST, we read in Matthew 13:23 - "And the one on whom seed was sown on the good soil, this is the man who hears the word and understands it; who INDEED BEARS FRUIT and brings forth, some a hundredfold, some sixty, and some thirty." *Only the 4th soil produced crops of any size.* The question may still remain, "can this forth soil eventually become fruitless?" I have to conclude that if this were possible, then why didn't Christ include such a scenario? There is mention of a difference in the size of the crops, but no consequences or warnings are given to the lesser producers. Only the 4th soil was referred to as "good ground" and produced a crop (fruit) and there is NO MENTION OF CHOKING OR WITHERING THEREAFTER.
The shallow ground hearer is contrasted with that of the "good ground" hearer, who's heart was "good" and "honest." Thus, his heart was "not good," being like the soil to which it corresponds, being "shallow" or "rocky," lacking sufficient depth. People who hear and receive the word with joy (emotional response) and believe (in a shallow way) without a good and honest heart, and without having no root do not experience real salvation. Temporary, shallow belief that has no root, lacks moisture, produces no fruit and withers away is not saving belief.
People in the NOSAS camp can't seem to make a distinction between genuine Christians and nominal Christians. I already showed you in John 2:23-25, where there belief (after seeing the signs that He did) was superficial in nature and Jesus would not commit Himself to those many people. Also, in John 8:31 where these Jews were said to have believed in Him, yet Jesus calls them out as slaves to sin, children of the devil etc..