When it comes to what could be called the most important subject in the Bible--the salvation of the souls of mankind--God's will is not secret, it is clear and plain. It often is perverted, but it is not secret, hidden, mysterious, or any other such adjective one may want to add.
Salvation is a simple message.
The RCC as well as many others want to obscure that simple message by adding works making it just like all the other religions of the world. We both agree that is heresy.
Early on the "work of baptism" was added perverting the message into baptismal regeneration, another heresy. Paul himself declared that his message was not hidden with man's wisdom but preached in clarity that all could understand:
1Co 2:1 And I, brethren, when I came to you, came not with excellency of speech or of wisdom, declaring unto you the testimony of God.
1Co 2:2 For I determined not to know any thing among you, save Jesus Christ, and him crucified.
1Co 2:3 And I was with you in weakness, and in fear, and in much trembling.
1Co 2:4 And my speech and my preaching was not with enticing words of man's wisdom, but in demonstration of the Spirit and of power:
It was the simple message of the cross.
1Co 1:18 For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.
--It was not a mystery unto them.
Act 17:30 And the times of this ignorance God winked at; but now commandeth all men every where to repent:
Act 17:32 And when they heard of the resurrection of the dead, some mocked: and others said, We will hear thee again of this matter.
Act 17:33 So Paul departed from among them.
Act 17:34 Howbeit certain men clave unto him, and believed:
--At the pinnacle of his message was the basic gospel: the death, burial and resurrection. At the point of the resurrection they made their decision whether to believe or not to believe in Christ. Some departed not believing. Others stayed with Paul because they did believe.
The entire message of the gospel is based on one thing: Will you believe this simple message that Christ paid the penalty for your sins? It is not a difficult message to preach or to understand. It demands a response. It demands that man has free will.
The denial of free will by the Calvinist shoots down TULIP.
That is the end-all and the be-all of it. The determinism of Calvinism cannot accept that man has a free will to receive or reject Jesus Christ as Savior. That one point in and of itself affects every one of the points of TULIP.
And in the "work" of baptism" they claim that God is doing the baptizing and not man. And yet the baptism God does is the circumcision done without hands, in other words in and by the Spirit. Last time I checked, water baptism was done by the hands of men.