First we should not be focused on number of bodies in the pews, we should be focused on preaching, teaching, and living out the Word of God. If we would, then we might just follow these...
Psalms 1:1 Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful.
This verse covers both those that continue to attend churches that they know are not teaching from Scripture as well as those that would send their children into the public schools to learn from the ungodly scornful sinners.
2 Timothy 3:15-17 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.
These verses tell us that we should be teaching our children the Scriptures so that they can be wise unto salvation...instead the vast majority send their children where they will never here the Scriptures but they will here about the latest educational methods and techniques...can we see the connection. When a culture stops teaching or listening to the Truth, all you are left with are techniques. And techniques will never save anybody...but they might fill a school or a church for awhile.
How can a church “grow” again...God gives the answer...
2 Chronicles 7:14 If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land.
Please notice the line “turn from their wicked ways”. God is talking to His people not the unbelievers. We as the Church need to turn from our wicked ways...and start relying on God and His Word instead of techniques...
The Secular Humanistic view of knowledge is Naturalistic Materialism. Meaning what can be known, can only be known by studying nature and matter. It's a closed system. It's also important to know that their view of knowledge is the more we know, the better we can fix this broken world. And because of Social Darwinism, man thinks he gets his value and dignity from being more attractive, more powerful, and more intelligent...tools needed for the Survival of the Fittest mentality. Thus we can see why there is a big push for education...and then more education. Then when your done, go back and get more education.
But what's interesting is that everyone of us that may have learned Algebra has at one point said, "Why do I need to know the Quadratic Equation? I'll never use this in real life." Inside we realize that gaining knowledge just for the sake of getting more knowledge is empty. The value and dignity we feel from such high intelligence is just the sin of pride and is never satisfying.
But under a Christian Theism worldview, knowledge is gained by two ways. General revelation (study of creation - think Ro 1:20) and Special revelation (the Word of God). General revelation is subject to Special revelation. The sole purpose of each is to reveal the character and mind of God, man's purpose, and man's redemption. You will NOT get this in a Public School system - BY GOVERNMENT MANDATE!
Thus, as we learn the Quadratic Equation, or E=(mc)(mc), or the intricacies of DNA, we stand in awe of God at how intelligent HE is. We glorify Him - not ourselves. We allow that which He has revealed to us to show us the proper way to have dominion over this earth (Gen 1&2). Education is bigger than just knowing stuff for self directed dignity and value. It's the knowledge of the very God who created us. Being created by Him, in His image is what gives us INHERENT value and INHERENT dignity.
Until the believers pull their children from government mandated secular humanistic schools, and give them the education that I believe God requires from parents, we are destined to continue to have these percentages...and to see them get worse.