It also counters gnosticism because if Jesus was sent to merely tell people that they are "divine" somehow and need to attain godhood, why would we need Jesus to overcome the enemy? The kind of lost souls who try to push gnosticism even try to deceive you into believing that God and the Bible are evil and false, so that you disregard them and don't acquire actual knowledge and wisdom so that you can live a life that is pleasing to the Lord and be blessed and saved. On top of that, the goal is also to get you to not use Scripture as a weapon against the enemy when engaging in spiritual warfare.
Gee, I wonder who could be the author of gnosticism? The same author of all false religions: the devil.
"Put on the full armor of God, so that you can take your stand against the devil’s schemes." (Ephesians 6:11, NIV)