Actually, since The Second is depicted as Christ too (savior), it's more likely he is his reincarnation than his son, but who knows.
Let's talk about another thing related. It's the connection between the first Adam and Christ,
the second (guess what?) and last Adam.
Between the first Adam and the Last (Christ) there's a contrast. And it's the following:
http://www.abetterhope.com/whois/adam.html
Now it's clear why Cruz reminded Kanna of Blade, right?
In a near future don't be surprised if Cruz shows some of Blade's traits such as, for example, his "verdict".