Can I Be Sure God's Spirit Lives Within Me?

In the light of certain movements within the ranks of Christianity and certain emphasis about the Spirit living in Believers, we must entertain the questions that some people and even Believers are asking. Here is a question in connection with the Holy Spirit’s indwelling; “How can a believer know the Spirit of God lives within?”
First understand that being filled with the Spirit is not the same as being indwelt by the Spirit. Receiving the Spirit and being controlled by the Spirit are two entirely different spiritual experiences. To be Spirit-filled means that the Spirit of God is freely working in and with you to achieve the will of God through you. To be Spirit indwelt simply means that God lives in us as a result of our repentance and faith in Christ the Lord. To be Spirit-filled is to be quite spiritual since the Spirit of God has incredible control of your life. To be Spirit indwelt does not necessarily mean that you are holy, set apart for God, nor consecrated to His will. It simply means that the individual is saved. All Believers are indwelt by the Spirit, but not all are Spirit-filled. Every Believer ought to walk in obedience and submission to the Spirit, but not all do. These two very different spiritual dynamics must never be confused; unfortunately many fail to recognize this important difference. In the New Testament, when we see terms like "filled""fullness" or "full" in relation to the Spirit of God generally it is referring to the Spirit-filled lifestyle. However, when we see terms like "receive," "have," or "dwell" these generally refer to being a Christian--Spirit indwelt. Actually this simple observation while reading the New Testament can clarify a great deal of confusion.
In addition a Believer can be filled with the Spirit repeatedly according to Ephesians 5:18, and we find this happening several times in the Book of Acts where Believers asked God to fill them afresh and anew for new power, standing for Christ, continuing in the will of God, and witnessing with boldness (Acts 4:23-37).Clearly some of these Christians were filled on the day of Pentecost in Acts 2, but in Acts 4 they are being filled again with the power and grace of God for life and service. We also know that Believers receive the Spirit once and only once that the Spirit may remain with us forever. He never leaves nor forsakes the Believer once He begins to live in us (John 14:16-18). We can grieve, vex, and quench the Holy Spirit, still He will not leave New Testament Believers as He did with some Old Testament Believers. With these preliminary observations established, we can now explore whether a genuine Believer can KNOW they are indwelt by God's Spirit.
Another way of asking this question is "Can we be sure we are indeed saved?" Since being indwelt by the Spirit is the same as being saved this is a good question. According to Max Anders (1995, Chapter 3) and Charles Ryrie (1995) there are two ways a Christian can know that he is indwelt by the Holy Spirit. First, simply take the Scripture at face value. If they have believed in and received Christ as their personal Savior, then they have the Spirit living within. Note John's exact words,

In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. 38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. 39 (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.) (John 7:37-39).

Here the Lord Jesus predicted that those who receive Him and believe on Him will receive the Holy Ghost as a result of their faith in Him. This reception of the Savior would transpire after the Lord Jesus was glorified. He was glorified through His resurrection, and through His glorious ascension to Heaven to His Father's right hand (John 17:1-10). Once there He and the Father sent the Holy Spirit to indwell all true Believers permanently.

Several scholars and Bible Commentators agree with this conclusion that the Spirit begins to indwell Believers at the moment we believe on Christ the Savior. Note just one insightful observation,

It is clearly stated that the expression “living water” refers to the Holy Spirit. Verse 39 is very important because it teaches that all who receive the Lord Jesus Christ also receive the Spirit of God. In other words, it is not true, as some claim, that the Holy Spirit comes to indwell people sometime after their conversion. This verse clearly and distinctly states that all who believe on Christ receive the Spirit. At the time the Lord Jesus spoke these words, the Holy Spirit had not yet been given. It was not until the Lord Jesus went back to heaven and was glorified that the Holy Spirit descended on the day of Pentecost. From that moment on, every true believer in the Lord Jesus Christ has been indwelt by the Holy Spirit. (MacDonald, W. (1995). Believer’s Bible Commentary)

Notice  furthermore the promise of our wonderful Lord Jesus. He indicated in clear terms the Spirit will pick up His work where Christ left off. He wanted to assure His disciples and us that we will not have to serve and labor alone! He was not abandoning His people!

And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; 17 Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you. 18 I will not leave you comfortless: I will come to you (John 14:16-18).

Our Lord promised another Comforter, one like Himself to remain with us Believers forever. The Comforter dwells in each Believer as Christ our Lord promised. This is clearly what the Lord Jesus taught in unmistakable terms. I believe Him and every Christian should take His words seriously! John 7:37-39, are clear about when a Believer is indwelt by the Spirit, and the Lord Jesus said it is when we believe. You see Christ has been glorified and is living today in Heaven as He predicted. He has sent the Spirit just as He promised He would. The Spirit is here and we are assure the Lord Jesus is back in Heaven and is glorified with the Father. Since He is glorified, and the Spirit is here operating in the world we now receive the Spirit the moment we believe on the Lord Jesus Christ. This wonderful promise of Christ continuing with His people through the indwelling Spirit is true for EVERY genuine Believer today with zero exceptions. 

Now there were a few exceptions to this in the Book of Acts when God sovereignly delayed the Spirit's indwelling the Samaritans (Acts 7), and the disciples of Apollos and John the Baptist (Acts 19). These were exceptions and not the standard or the rule. God had specific reasons for delaying the Spirit's indwelling these people groups. Because of these delays, His Apostles were assured of the truth that the Gospel is for all peoples, all nations, and the message was to be taken to the uttermost parts of the globe (Acts 1:8). Apostle were present to witness what God was doing internationally regarding the Gospel and the salvation of anyone who repented and believed the Gospel. The Gospel is for Jews, Samaritans, and Gentiles; God desires to save all and is not willing that any should perish. To signify this God delayed the Spirit's indwelling in these few instances to demonstrate this truth to His leaders the Apostles. Again these were exception and not the rule. The standard procedure is for a person to repent believing the Gospel of Christ, and they are saved, regenerated, and indwelt by the Spirit of God exactly as the Lord Jesus said it would be. This is the standard as demonstrated in Acts 10 when Cornelius and his household are marvelously saved. Peter preaches the Gospel, they listen with believing receptive hearts and God's mighty Spirit fell upon them all. As new Believers they received the Spirit of God in a manner that was obvious to the Apostle Peter--they were genuine Believers. Yes, God was signifying that even Gentiles should hear the Gospel and be saved by grace. Peter would later explain all of this to the church in Jerusalem and they finally accepted Gentiles as true Believers (Acts 11). The order again is simple: the Gospel is preached, sinners listen with repentant and believing hearts, and God saves them giving them the Spirit of God to indwell them. Beloved this is the rule; yes, there are a few historical exceptions, but this is the rule.   

We can stand on the clear statements of God’s Word. In fact, Romans 8:9 makes it clear that if we do not have the indwelling Spirit then we are not saved at all. In contrast, if we do have the indwelling Spirit, we are truly saved. Indwelling is a normal consequence of faith in the Lord Jesus Christ as Savior. It is not a "second blessing" of some sort; it is the reception of Jesus Christ through the Spirit of Grace upon our repentance and faith in Christ.

The second way is to look for the evidence of His work in one’s life (Ryrie, C.). This too can afford assurance of the Spirit’s indwelling. When I became a Christian, I was certain I was, because things within me were changing. Though I struggled later with assurance issues rooted in bad theology, initially I had great assurance. New desires, motives, and ambitions were beginning to emerge. Over the next few weeks, I would continue my work at the aircraft support equipment shop of Plattsburgh, AFB, New York. But now it really bothered me when my co-workers and fellow airmen were swearing or using vulgarities. This in spite of the fact that a few weeks before I was the ring leader in that circus, but now I wanted everybody to stop. Before my conversion I freely participated in the generous usage of expletives, gutter language, and filthy statements. Now God was cleaning up my speech and I wanted others to clean theirs up also.  

I could recall also changing my TV and Cable watching selections and habits; I seemed to know instinctively that my previous selections were inappropriate for a Believer. I also embraced new friends and curtailed my involvement with old friends who could influence me to live the old life. On the other side of things, I found myself reading my new Bible and loving it, especially the Book of Genesis; I truly was fascinated and thrilled. The Spirit began to teach me and formulate wholesome values within. I began attending the church I was saved in on Sundays, and developed a desire to be with and talk to other Christians about spiritual things. I recall the emergence of desires to be more loving, less prideful, holy, and more patient springing up deep within me. I also felt burdened to reach my old friends with the Gospel and I began inviting them to church. My life was far from holy and consecrated to God, but these small changes within evidenced the Holy Spirit’s internal work.

The Spirit had indeed moved in and was about the work of growth and transformation.  Not everyone’s experience will be the same as this, but such positive “changes” are indications of the indwelling Spirit of God. With regard to experiences, it would be wise to think on the words of Charles Ryrie (1995) in A Survey of Bible Doctrine,

Experience may not always be convincing since sin may hinder His work, and in the normal process of Christian development one’s growth will be slow but steady with no unusual demonstrations of the power of God. This unspectacular kind of progress should never be diagnosed as indicating the absence of the indwelling Spirit. He does abide forever in every believer’s life (Jn. 14:16–17).

Finally, because the Spirit indwells Believers, we are never alone. Prisoners in concentration camps or prisoners of war camps testify that the presence of God kept them going during the grueling hours, days, and even years of solitude. This is because they knew they were not really alone. Praise the Lord for His eternal Presence in and with His people always (Anders 1995, Chapter 3)! Even after exploring these very clear passages and examining the biblical facts, the Spirit’s indwelling is still mysterious in some regards. Obviously there are some things we Christians know for certain, but others evade our understanding heretofore. The concept of indwelling is such a mystery that probably no one fully understands specifically what happens in that instant the Spirit of God moves inside. But indwelt Believers truly are if they have given their lives over to faith in Christ. The Scriptures makes it clear that the Holy Spirit lives in us, and based on that fact, we should glorify God with our bodies.