- the reading of the Bible.
Have you "graduated" then from reading the Bible because of some advanced maturity ?
Reading the Bible is "milky" activity for you now ?
- understanding the basic precepts of Christian life
- singing of hymns
When Jesus sang a hymn along with His disciples did that manifest His spiritual infancy far below your level of meat eating maturity ?
" And after singing a hymn, they went out to the Mount of Olives. " (Matt. 26:30)
Was the Lord Jesus showing some sort of spiritual adolescenthood just before going to be arrested and crucified?
Is Paul's instruction to speaking to one another in songs and spiritual songs designed to keep the church in Ephesus
underdeveloped and immature ?
" ... but be filled in spirit, speaking to one another in psalms and hymns and spiritual songs, singing and psalming with your heart to the Lord." (Eph. 6:18b,19)
Is this exhortation too much milk like Christian practice for you ?
- the meetings and companionship
So when Paul wrote of his companions he was too much in the infantile "milk" of Christian living ?
IE. When he writes some letters now part of the word of God ?
"Paul, a called apostle of Christ Jesus through the will of God, AND SOSTHENES the brother." ( 1 Cor. 1:1)
"Paul, an apostle of Christ Jesus through the will of God, AND TIMOTHY the brother, ..." ( 2 Cor. 1:1)
"Paul and Silvanus and Timothy to the church of the Thessalonians in God ..." (1 Thess. 1:1)
"Paul and Timothy, slaves of Christ Jesus, ..." (Phil. 1:1a)
"Paul, an apostle of Christ Jesus through the will of God, AND TIMOTHY the brother, to the saints in Colossae ..." (Col. 1:1)
"Paul AND SILVANUS AND TIMOTHY to the church of the Thessalonians ..." (2 Thess. 1:1)
So the Apostle Paul was displaying his spiritual milk drinking immaturity by writing these letters with companions ?
- the calling of Jesus name
- the praying
You have graduated from calling on the name of the Lord Jesus ?
You are no longer immature to have need to PRAY ??
David said he would call on the name of Jehovah to be saved from his enemies.
"I called upon Jehovah, who is worthy of praise and from my enemies I was saved." (Psalm 18:3)
I call on the name of the Lord Jesus every day to be saved from some enemies of my soul. So it is "milk" of the word of God to want to be saved from your spiritual enemies by calling on the name of the Lord Jesus ?
Becoming more spiritually mature does not cause the Christian to "graduate" somehow from any of the things you have listed here.