God is considered the author of sin because He ordains all things and has decreed that sin exists, but He does not sin Himself.
The concept of God as the author of sin can be confusing, but it is vital to understand that this does not mean that God Himself sins or is morally corrupt. Instead, it points to God's sovereignty in allowing and utilizing sin to accomplish His redemptive purposes. The phrase 'God is the author of sin' must be understood in light of His perfect will and nature. Romans 9:17 clearly indicates that God raised Pharaoh for the purpose of demonstrating His power, allowing Pharaoh to act wickedly, which serves to glorify God. Thus, sin is utilized by God within His providential plan, showing that He is ultimately in control of all things, including the actions of sinful men, without being guilty of sin Himself.
Scripture References:
Romans 9:17, Acts 2:23, James 1:13-14
Commentary