Works salvation denies the sovereignty of God, His unconditional election, predestination, foreknowledge. It denies His power to save sinners from their sins which has made man a slave to it, this is why they need to be born again by the grace and His great love for His people.
Ephesians 2:4-7 “But God, being rich in mercy, because of the great love with which he loved us,5 even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved—6 and raised us up with him and seated us with him in the heavenly places in Christ Jesus,7 so that in the coming ages he might show the immeasurable riches of his grace in kindness toward us in Christ Jesus.”
He made us alive with Christ because of His great love for us, we love Him because He first loved us I John 4:19 “We love Him because He first loved us.”
The idea of works salvation goes against what the Bible teaches about salvation by grace through faith. The doctrine it goes against with-in the doctrine of salvation is justification, because it is by faith and faith alone it is a gift from God.
Romans 12:3 “For I say, through the grace given to me, to everyone who is among you, not to think of himself more highly than he ought to think, but to think soberly, as God has dealt to each one a measure of faith.”
If the Lord does not justify us we are guilty as charged to be judged to an eternity in eternal flames of fire, once justified by the Lord we can never be charged for our sins again. If we were that would be double jeopardy and the Lord would be unjust and we know He is not unjust so our salvation is gaurunteed by Him by His Spirit He seals us until the day of Jesus Christ, no works can gauruntee anything because us as man fail all the time.
Works salvation makes man God and God man or as Romans 1:18-23 put it, works salvation bring these Scriptures alive.
“For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth.19 For what can be known about God is plain to them, because God has shown it to them.20 For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.21 For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened.22 Claiming to be wise, they became fools,23 and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.”
Because it takes the attributes of God in His election, grace, predestination, sovereignty, foreknowledge and mercy in salvation and transfers them to man in his self will to save himself by chosing God over God chosing certain humans to salvation. They have now made man to have these attributes unto salvation, man takes the glory for his own salvation and does not glorify God in his salvation, because man brought it about on his own, which clearly goes against Ephesians 2:9
“For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,9 not a result of works, so that no one may boast.10 For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.”
The works salvation twists these Scriptures to be read as it is saying that faith is what bring about grace, when in chapter 1 we see what faith means for those that are the righteousness of God through Christ.
Romans 1:16-17 “For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek.17 For in it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.”
We live by faith, we are saved by grace and live in that grace by faith this is what Ephesians 2:8 is saying it is not saying that it is faith that brings grace verse 5c tells us how we were saved, “by grace you have been saved” we are saved by grace and we live in the righteousness of salvation by faith as we are told in chpater 1 verse 17, grace is not obtained by faith we live in the righteousness that it imputes to us by faith.
Works salvation glorifies man and makes God as having the power of a mere man, because man saves himself over the Lord saving him by His good pleasure Ephesians 1:11-14
“In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will,12 so that we who were the first to hope in Christ might be to the praise of his glory.13 In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit,14 who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.”
Our salvation is according to the councel of His will we were predestined, He predestined us and when we heard the word of truth, we believed and were sealed by the promised Holy Spirit who guarantees our salvation to the praise of His glory. He predestined us to salvation, we respond to the word of truth by believing in Him, then we are sealed until we receive the inheritance of our salvation all to the praise of His glory. Our salvation is all by Him, we respond to Him in faith/believing/repentance and we are seal with the promised Holy Spirit until the day that salvation is fully come in the regeneration of the earth as well as our bodies. Hallelujah our salvation is all God and our responce in faith.