To walk in the Spirit requires some preparation; such as growing past being a babe in Christ, who no longer needs to learn the first principals of the oracles of God as Christ is being formed within; Tit 3:5, "Not by works of righteous that we have done, but according to his mercy he saved us, by the washing of regeneration and the renewing of the Holy Spirit. The work of the washing of regeneration can be seen in; Eph 5:26 "That he might sanctify and cleanse it with the washing of water by the word." The renewing of the Holy Spirit's work is seen in; Rom 12:2 "And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God."
These scriptures are referring to a process of repentance, where the new believer is sanctified and cleansed by being transformed by the renewing of the mind and able to prove the good, acceptable, and perfect will of God. This milk of the word deals with the repentance part of the first principals of the oracles of God and is for the babes in Christ, whereas strong meat of the word is for the mature who by reason of use have had their senses exercised to discern both good and evil. The first principals of the oracles of God are like a road map of growth for the new believer, which begins by laying a foundation of repentance from dead works and of faith towards God. Then baptisms, proclaiming publicly that they are dead and buried with Christ and raised in the newness of life in Jesus, to follow the leading of the Spirit. Body ministry comes with the laying on of hands and then on to teachings about the resurrection of the dead and eternal judgment, which should be the Church's burden for the lost.
As sin after sin is dealt with in the new believer, who comes the Lord by faith just as they are; and Holy Spirit applies the blood of Jesus to purge the conscience from dead works; so that there is no more conscience of those sins that have been dealt with by the Spirit, and the water, and the blood. While having Christ being formed within, the Spirit is reproving the believer for righteousness, writing the Lord's NT commandments that we study onto the table of our hearts and minds, here a little and there a little. Soon the things that were once enjoyed, one by one, usually, become points of conviction as the conscience is renewed by the ministry of the Holy Spirit. In fact, the Holy Spirit will even use our own guilt as a tool to set us free from the most irresistible of sins as he transforms us into Jesus' moral image.
This cleansing and renewing and purging brings about a joy unspeakable and full of glory attitude in the believer's heart; so much so, that often such a one seeks to learn more songs just to express the intensity of the emotion being felt. It is then that one is able to deny the lusts of the flesh while walking in obedience to the Holy Spirit as the joy of the Lord becomes our strength.

Jn 16:8 "And when he is come, he will reprove the world of sin, and of righteousness, and of judgment."

Gal 4:19 "My little children, of whom I travail in birth again until Christ be formed in you,"

Heb 10:1,2 "For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect. For then would they not have ceased to be offered? because that the worshippers once purged should have had no more conscience of sins."

Heb 5:12-14 "For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. For every one that useth milk is unskilful in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil."