The born-again Christian is, in the psychological vernacular, bi-polar. Every one of us has periods in which we are filled with the Holy Spirit, and others in which we are full of ourselves. Jesus told His disciples that although they had the Holy Spirit dwelling with them, soon He would be dwelling within them (Jn. 14:17). In fact, from the Day of Pentecost when the Holy Spirit filled all of the Lord's disciples (Acts 2:1-4), every born-again member of the Body of Christ (1 Cor. 12:27) owes his regeneration to the indwelling of the Holy Spirit (Jn. 3:3-8; Rom. 8:9).
However, having the Holy Spirit within us does not necessarily mean that we are filled (totally under His control). Apparently Christians leak! Evidence of that is found by comparing Acts 2:4 and 4:8; the Apostle Peter was filled on the Day of Pentecost, and again when he was taken before the Jewish leaders. The same is true of the Apostle Paul (compare Acts 9:17 and 13:9). If believers were filled with the Holy Spirit all of the time, Paul would not have had to admonish believers in Ephesus not to be drunk with wine, but to be filled with the Spirit (Eph. 5:18).
At any given time, born-again Christians are either carnal, or they are spiritual; there is no "gray area" between the two. When we are filled with the Holy Spirit, we have the character of Christ. We manifest the "fruit of the Spirit" (Gal. 5:22-23). When we are walking in the flesh, we manifest the "fruit of the flesh" (Gal. 5:19-21). Paul describes believers who are not filled with the Spirit as being carnal. The Greek word translated carnal is σάρξ (sarx), which means "the flesh," and it refers to our human nature, the earthly nature of man apart from divine influence, and therefore prone to sin and is the opposite of godliness.
Paul made the contrast clear when he wrote, "And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, [even] as unto babes in Christ" (1 Cor. 3:1). In another place, Paul wrote, "[This] I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would" (Gal. 5:16-17). Paul was definitely speaking from experience (Rom. 7:15-25). Peter described immature believers as "babes" and admonished them to "desire the sincere milk of the word, that ye may grow thereby" (1 Pet. 2:2). Peter had a problem with this on at least two occasions (Acts 10:9-34; Gal. 2:11-14).
If the two most famous Apostles had a problem with "leaking," is it any wonder that you and I have as well? The solution is simple; carnality is sin, and sin makes us unrighteous. Confession of sin restores us to the righteousness of God (1 Jn. 1:9). I don't know about you, but I need 1 John 1:9 many times a day! Thank God He is a merciful, patient, and loving Father to His "bi-polar" children!