Christianity is an exclusive proprietary club, if you will. It belongs only to those who have believed in Christ, the Son of God, the Savior, the Messiah, as He has been identified throughout the ages.
Those who do not believe in Christ, unbelievers, do not have access nor a right to the things of the spiritual life.
Within the Christian life, there are various levels of proprietary privilege.
As one studies, learns and grows up in their spiritual life, thus advancing toward spiritual maturity, then the productions of the spiritual life belong to them, and therefore the rewards of eternity belong to them.
Those who do not learn, do not grow and thus do not advance toward spiritual maturity, do not have nor have access to, the rewards or spiritual maturity.
Those who comply with Gods established process for spiritual growth, do in fact grow.
Those who do not comply with Gods established process for spiritual growth, do not grow up.
To those who are obedient to Gods mandates, God acknowledges and blesses.
To those who are not obedient to Gods mandates, we have our current verse. Enough! No more! Stop!
Far too many people approach God by means of their own defined righteousness, and they are wrong.
Far too many people attempt to gain access to the spiritual life through their emotions, and they are wrong.
Far too many people attempt to portray themselves as spiritual in order to impress others, and they are wrong.
Far too many people ignore Gods mandates for confession, for study, for learning, for application of Gods doctrines, and they do not have a functional spiritual life. And yet they persist in singing and speaking and pursuing their erroneous ideas of spirituality, and God says, ‘Enough!’
People pursue their false approaches to God, on the Sabbath’s (regular weekly gatherings), on the new moons (special holiday gatherings), in the calling of assemblies (activities within the weekly or special festivals or gatherings).
And all of these activities, are for nothing, when they do not comply with Gods mandated spiritual process. They are vanities within vanities. They are abominations within abominations.
And though you may be impressed with your own efforts, or you may think that you are impressing others, or you may be impressing others with your efforts and expressions, the one person who you should be directing your efforts toward, namely God, is not impressed, but on the contrary rejects all of your impotent efforts.