Why are children considered sinners even at birth according to Reformed theology?

According to Scripture, particularly seen in Romans 5:12, sin entered the world through Adam, and as a result, death spread to all, because all have sinned. This includes individuals at birth, as they inherit the original sin of Adam. Thus, even infants are born with a sinful nature, which is emphasized by the belief that every human is counted as a sinner by virtue of their identification with Adam. They are not innocent but are born in a state of sin, highlighting the necessity of divine grace for salvation.