We are to mature in understanding of the scriptures.
We are body, soul (mind) and spirit.
Those born of God have been created as having a new alive spirit inside of them, one that is spiritually in fellowship with God, joined as one spirit with Him, regardless of the age or maturity level of the saved person. We need to align our minds with the Word of God. But our spirits born of God are already perfected spiritually and do not sin as apostle John says and Paul writes we were created according to the will of God in true righteousness and holiness, the inner man of the spirit.
1 John 3:9 Whoever has been born of God does not sin, for His seed remains in him; and he cannot sin, because he has been born of God.
Spiritually we do not need to know gnostically spiritual truths to be born of God.
Those who are born again, Jesus tells us to marvel not, it is not under your control, they are born according to the Spirit and not the will of the flesh. And God reveals the things of God from His Spirit to our spirits the deep things of God.
Ephesians 4
The New Man
17 This I say, therefore, and testify in the Lord, that you should no longer walk as the rest of the Gentiles walk, in the futility of their mind, 18 having their understanding darkened, being alienated from the life of God, because of the ignorance that is in them, because of the blindness of their heart; 19 who, being past feeling, have given themselves over to lewdness, to work all uncleanness with greediness.
20 But you have not so learned Christ, 21 if indeed you have heard Him and have been taught by Him, as the truth is in Jesus: 22 that you put off, concerning your former conduct, the old man which grows corrupt according to the deceitful lusts, 23 and be renewed in the spirit of your mind, 24 and that you put on the new man which was created according to God, in true righteousness and holiness.