If believing, for salvation, isn't a work, what is?
It's a passive response to God's promise through His Son.
I gave 2 passages. Didn't you see the distinction make between works and grace?
Works create a debt or obligation. Grace is free. One can't work for it or earn it.
Circumcision, dietary laws, tithing, feast keeping, sabbath days, days of atonement, temple worship, etc. are the works Paul taught were unnecessary for salvation.
Correct.
Not hearing, believing, having faith, confessing, repentance from sin, baptism in Jesus' name for the remission of past sins, or continued obedience to God.
Hearing and believing are passive responses to the gospel.
Confession, repentance from sin, water baptism and 'continued obedience to God' are ALL WORKS.
No where in the Bible will you read that any of those things will result in salvation.
God makes new creatures that can remain obedient till the end!
And God knows that no one will. So He provided the means of forgiveness and cleansing from our sins in 1 John 1:9.
Rom 6:3-5
3 Or don’t you know that all of us who were baptized into Christ Jesus were baptized into his death?
4 We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.
5 For if we have been united with him in a death like his, we will certainly also be united with him in a resurrection like his.
This passage shows our identification with Christ in His own death, burial and resurrection. This is known as positional truth. Because the believer is in union with Christ (in Him), we are identified in what He went through.
And v.4 shows that water baptism is a symbol or represents our identification with Christ.
Here are some verses that refute your claim that believers become sinless permanently.
Rom 6
11 In the same way, count yourselves dead to sin but alive to God in Christ Jesus.
This verse doesn't say we ARE dead to sin, but to COUNT yourself dead to sin.Thi
12 Therefore do not let sin reign in your mortal body so that you obey its evil desires.
This verse proves that the believer CAN still sin, by the command to "do NOT LET sin reign in your mortal body". If a regenerated person no longer has a sin nature, this command is worse than useless. It would be absurd.
13 Do not offer any part of yourself to sin as an instrument of wickedness, but rather offer yourselves to God as those who have been brought from death to life; and offer every part of yourself to him as an instrument of righteousness.
More evidence that believers CAN offer parts of their bodies to sin.
15 What then? Shall we sin because we are not under the law but under grace? By no means!
Here, Paul even asks if we should sin? Obviously, we CAN. Not that we should. But you claim a regenerated person cannot sin.
16 Don’t you know that when you offer yourselves to someone as obedient slaves, you are slaves of the one you obey—whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness?
This verse shows the choice EVERY believer has, including yourself. It's a choice about to whom you offer yourself as a slave; either to sin or righteousness.
But it is a choice, yet your claim is that a regenerated person cannot sin.
Now consider what Paul taught in 1 Cor 5
5 hand this man over to Satan for the destruction of the flesh, so that his spirit may be saved on the day of the Lord. This refers to the incestuous believer in the congregation. Paul's warning is physical death at the hand of Satan.
11 But now I am writing to you that you must not associate with anyone who claims to be a brother or sister but is sexually immoral or greedy, an idolater or slanderer, a drunkard or swindler. Do not even eat with such people.
12 What business is it of mine to judge those outside the church? Are you not to judge those inside?
In v.11, the words "claims to be a brother" is not accurate. The tense is passive and means "anyone considered to be a brother". iow, thought to be a fellow believer by others, not by their own claim.
In v.12, Paul distinguishes between NOT judging unbelievers (those outside the church) but having discernment of believers (those inside).
If you still want to think the incestuous guy or those considered to be a brother are not really saved, Paul had more to say on the subject.\
1 Thess 3
14 Take special note of anyone who does not obey our instruction in this letter. Do not associate with them, in order that they may feel ashamed.
15 Yet do not regard them as an enemy, but warn them as you would a fellow believer.
Obviously Paul knew that some believers would misbehave. And while we are commanded to not associate with them, same as in 1 Cor 5, we are NOT to regard them as an enemy, but warn them as a fellow believer.