CB- Thus God knew very well about Adams character, what would happen, and ordained it to happen.
This doesn't make God an "author of sin". But you have my curiosity aroused since you're saying it does. Let's break this apart.
2) God knew what would happen
3) God ordained it to happen
Ordained
1.
a. To invest with ministerial or priestly authority; confer holy orders on.
b. To authorize as a rabbi.
2. To order by virtue of superior authority; decree or enact.
3. To prearrange unalterably; predestine Synonyms dictate
By stating that God ordained someone to sin the would mean that God ordered that person to sin. God does not order, decree or authorize sin.