Every believer can, like Paul, be filled with the Holy Spirit at the time he believes and is baptized (Acts 9:17-18). However, many believers do not truly believe as an accomplished fact that Christ has died and been resurrected for them, nor do they sincerely apply in practice the principle of death and resurrection which they are called by the Holy Spirit to obey. Hence, they still remain subject to the control of the flesh, just like those who have not died and been resurrected, although in fact, they have died and been resurrected according to what has been accomplished by Christ, and they should die to themselves and live to God according to their duty as disciples. This type of believer may be said to be abnormal. But abnormal believers are not found only today; they were already in existence at the time of the apostles. The Corinthians are a case in point, as we may see from what Paul said to them:
"And I, brothers, was not able to speak to you as to spiritual men, but as to fleshy, as to infants in Christ. I gave you milk to drink, not solid food, for you were not yet able to receive it. But neither yet now are you able, for you are still fleshly. For if there is jealousy and strife among you, are you not fleshly and do you not walk according to the manner of man?" (1 Cor. 3:1-3).
Here the apostle divides all Christians into two categories: the spiritual and the carnal or fleshly. Truly spiritual Christians are in no way extraordinary Christians; they are simply normal. It is rather that the fleshly Christians are the extraordinary ones for they are in reality abnormal. The Corinthians were already Christians, but they were not spiritual; rather, they were fleshly. Three times in this chapter of the Bible the apostle said they were fleshly. The apostle knew through the wisdom bestowed on him by the Holy Spirit that he should first know to which group they actually belonged before he could determine what the doctrinal truth was that should be ministered to them.
In the light of the Scriptures, regeneration is a birth. When one is regenerated, the spirit that lies hidden in the innermost part, the deepest part, of his being is renewed and indwelt by the Spirit of God. However, time is needed for the power of this new life to extend outward from the center to the circumference. Therefore, we cannot expect a babe in Christ to have the strength of the "young men" or the experience of the "fathers." In the case of a newly regenerated believer, even if he loves the Lord to the uttermost, is very fervent in his service, and goes on most faithfully with the Lord, time must still be given him so as to afford him the opportunities to better recognize the detestfulness of sin and self and to better understand God's will and way in the spiritual life. Of course, among these believers there are often some who really do love the Lord with exceeding fervor and greatly delight in the truth, but this still is nothing more than the operation of the emotion and the mind, untested by fire, and consequently not lasting. In any case, it is unavoidable for a newly regenerated believer to remain fleshly because he does not know the flesh even though he is filled with the Holy Spirit. One cannot eliminate the works of the flesh if he does not realize that these works are the products of the flesh. Hence, in reality many newly born believers are truly of the flesh.
The Bible does not expect a Christian who has just believed in the Lord to immediately become spiritual. However, if he makes no progress whatever for years, or even for decades, and stays in the position of a babe, this is not proper, and his case is most pitiful. After speaking about babes in Christ being of the flesh, the apostle proceeds to state that those who have remained as babes for a long time are also of the flesh. Of course, this is so. Prior to that, Paul considered the Corinthian believers as being of the flesh, as being babes in Christ, but even at that time they were still of the flesh. By that time they should have grown into adulthood, but on the contrary they had withered away, so much so that they remained babes. Consequently, they were still fleshly believers.