Who is the unseen person walking, hearing and knowing every thought of the mind?

 

Many make reference that this next quote is talking about another person separate from Christ called the "holy spirit":

“We need to realize that the Holy Spirit, who is as much a person as God is a person, is walking through these grounds, unseen by human eyes; ... He hears every word we utter and knows every thought of the mind.” Evangelism p. 616 

But, who is this unseen person walking, hearing and knowing every thought of the mind?

"Christ walks unseen through our streets. With messages of mercy He comes to our homes.”  Ministry of Healing, p. 107

“How few realize that Jesus, unseen, is walking by their side! How ashamed many would be to hear His voice speaking to them, and to know that He heard all their foolish, common talk!"  Manuscript Releases, Vol. 14, p. 125 

“I have been instructed that we should lead the sick in our institutions to expect large things because of the faith of the physician in the Great Healer who, in the years of His earthly ministry, went through the towns and villages of the land, and healed all who came to Him. None were turned empty away; He healed them all. Let the sick realize that, although unseen, Christ is present to bring relief and healing.” — Letter 82, 1908 

“Jesus desires to make celestial harmony in your soul. Read His words, not with discouragement, but with confidence and hope. Listen to the blessed words which God speaks to you. Walking with Christ means to believe that, though unseen, Christ is walking with you." — Letter 104, August 4, 1901  

“Remember that Jesus is beside you wherever you go, noting your actions and listening to your words."  The Youth Instructor, Feb. 4, 1897 

“Go forth in the name of Christ, remembering, that he is your companion, that every prayer, every word, every song is heard by him. The message of the soon coming of the Lord with power and great glory will bring conviction to many hearts.” RH, February 4, 1904 

“The Lord Jesus standing by the side of the canvasser walking with them, is the chief worker. If we recognize Christ as the One who is with us to prepare the way, The holy spirit by our side will make impressions in just the lines needed. " Colporteur Ministry, p. 107

 “The human agent, the seen instrument, is to preach the Word, and the Lord Jesus, the unseen agency, by His holy spirit is to make the Word efficacious and powerful." Letter 105, 1900

If Jesus is in heaven, how then does He walk with you?     “By the Spirit the Father and the Son will come and make their abode with you.” Bible Echo and Signs of the Times, January 15, 1893