Somebody wrote, “People do what is inspected, not what is expected.” We tend to work harder when the boss is around. Now, imagine the implication of having the Holy Spirit in you.
But, first, what does it mean when the Bible says that we have the Holy Spirit within us? “[Do] you not know that your body is a temple of the Holy Spirit within you, whom you have from God?” (1 Corinthians 6:19. Emphasis added. See also Romans 8:9) 
Does it mean He is physically located in our bodies? Remember that He is not material but spiritual. Hank “Bible Answer Man” Hanegraaff’s article on “The Indwelling of the Holy Spirit” clarified that the preposition “in” is not always used literally but also figuratively. When we say that a person will always be “in our heart,” we use that preposition as “a figure of speech to describe a relationship of love.” 
The danger of ascribing physical location to the Person of the Holy Spirit is that it logically implies that the Holy Spirit is by nature a material being. When 1 Corinthians 6:19 says the Holy Spirit is in you, it is describing a personal relationship rather than a physical location. Thus to say that the Holy Spirit is in you is not to point out where the Holy Spirit is physically located, but rather to point out that we have come into a special, intimate, personal relationship with Him through repentance. … He is not speaking of physical location but intimacy of relationship. 
|“Thus to say that the Holy Spirit is in you is not to point out where the Holy Spirit is physically located, but rather to point out that we have come into a special, intimate, personal relationship with Him through repentance. … He is not speaking of physical location but intimacy of relationship.” Hank “Bible Answer Man” Hanegraaff. Image credit|
Now that we know what it means that the Spirit is in us, the second question is, what does it mean to us? Let us not miss out on the truth that the indwelling of the Spirit has to do with “intimacy of relationship.”
So you have not received a spirit that makes you fearful slaves. Instead, you received God’s Spirit when he adopted you as his own children. Now we call him, “Abba, Father.” For his Spirit joins with our spirit to affirm that we are God’s children. (Romans 8:15-16, NLT)
The presence of the Spirit in us should be a cause for joy, not fear. It’s like having your closest friend with you as you go through the ups and downs of life.
Having the Spirit in us is an affirmation that we are indeed part of the family of God. Because of that, we have the closest relationship ever with Him. As Pastor Timothy Keller of Redeemer Presbyterian Church in New York City sent via Twitter,
The only person who dares wake up a king at 3:00 AM for a glass of water is a child. We have that kind of access.
One of the blessings of having the Holy Spirit in us is the unhindered and unlimited access we have before God. Reflect on Romans 8:26-27. As we pray (and even in those times that we could only be silent before God), the Spirit prays with us and for us. Rejoice that the Spirit is in you, that you have “a special, intimate, personal relationship with Him”!
NOTE: This is Day Two of the devotional guide (Volume 1, Issue 5) of our church, Filinvest Community Christian Fellowship, for the message last Sunday, March 29, on “Know How Much You Are Worth Part 3” (“Significance” series, a verse-by-verse study of the book of Ephesians).
 All Bible verses are from the English Standard Version, unless otherwise noted.
 Hank Hanegraaff (2009, June 10), “The Indwelling of the Holy Spirit,” Christian Research Institute, retrieved from http://www.equip.org/.
 Ibid. Italics his. Emphasis added.