Arius was extremely sly because he used what appeared to be all the right Christian lingo, but - and this is important - he interpreted the words differently, which is something all cults do today.
In 325, the council of Nicea ruled decisively against Arianism and it is very instructive to see how detailed and committed they were to preserving the key doctrine of Christ's deity - it basically came down to one small letter. All that Arius and crew wanted was to have it said that Christ and His Father were homoiousion, or "of like substance". But the orthodox council instead insisted that Christ and the Father were homoousion, or "of the same substance". One letter- an "i" - meant all the difference to the early Christian apologists. The famous Nicene Creed clearly spells this out, with the first part reading:
We believe in one God, the Father Almighty, maker of all things visible and
invisible; and in one Lord Jesus Christ, the Son of God, the only-begotten of
his Father, of the substance of the Father, God of God, Light of Light, very God
of very God, begotten not made, being of one substance with the Father.
No mistaking that position! I so wish the church today was as detailed and vigilent about protecting the key doctrines of the Christian faith as were our previous defenders.
I just completed a new set of materials on one of the modern day Arian movements - the Jehovah's Witnesses - who cling to the false doctrine that Christ was made and is not fully God. You can find the article, summary sheet, powerpoint, and podcast on my web site at http://www.confidentchristians.org/resources.html.