It wa a heresy that attempted to find a compromise between the Catholic Faith and Arianism. At the Council of Nicaea (325 A.D.), it was declared that the Son of God is "of the same substance" (homoousion) as the Father. This was included in the Nicene Creed. Some bishops had a legitimate concern that the term "substance" could be misunderstood to imply that God is of matter instead of pure Spirit. Whereas, other bishops did not like the precision of the term. They wanted a vaguer term to describe the Father and the Son. These Semi-Arian bishops substituted the term "homoousion" in the Nicene Creed with the term "homoiousion", meaning "of like substance". They hoped that this compromise would be acceptable to both Catholics and Arians. The Semi-Arians quipped that the only difference was a diphthong. Unfortunately the true Arian believed that the Son was "unlike" the Father. Also the term "like" is too weak to describe the unique relationship between the Son and the Father. According to Genesis 5:1, "When God created man, He made him in the likeness of God." The term "like" can also be used to describe the relationship between God and man. Furthermore a photograph of myself has a likeness of me, yet it is still substantially different than me. Either the Son is "of the same substance" as the Father, or the Son is "unlike" the Father in substance. There is no compromise.
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