Isaiah 59:17 (a) A symbol of the blessing that comes to the one who is saved. His thoughts are guarded and his decisions are in the fear of GOD.
Ephesians 6:17 (a) This represents the provision GOD has made in His salvation for protecting the mind, the thoughts, and the mental processes. The mind is renewed by the Holy Spirit. It is enlightened by the Word of GOD and all of this is compared to a helmet. (See also1Th 5:8).