It is God's grace in saving that He shows His long-suffering. Christ, who was put to death for our sins, is the Example par excellence of how we, in imitation to Him, ought to be patient and long-suffering.
But Peter very much is talking about salvation. God in His patience is gracious toward us. Just as He was gracious toward Noah and his family, so He is gracious toward us in saving us.
You're not wrong about most of the context, but you seem to be evading a clear point of the text.
"But even if you should suffer for righteousness' sake, you will be blessed. Have no fear of them, nor be troubled, but in your hearts honor Christ the Lord as holy, always prepared to give answer to anyone who asks you for a reason for the hope that is in you, yet do it with gentleness and respect, having a good conscience, so that, when you are slandered, those who revile your good behavior in Christ may be put to shame. For it is better to suffer for doing good, if that should be God's will, than for doing evil.
For Christ also suffered once for the sins, the righteous for the unrighteous, that He might bring us to God, being put to death in the flesh but made alive in the spirit, in which He went and proclaimed to the spirits in prison, because they formerly did not obey, when God's patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were saved through the water. Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ, who has gone into heaven and is at the right hand of God, with angels, authorities, and powers having been subjected to Him.
Since therefore Christ suffered in the flesh, arm yourselves with the same way of thinking, for whoever has suffered in the flesh has ceased from sin, so as to live for the rest of the time in the flesh no longer for human passions but for the will of God. For the time that is past suffices for doing what the Gentiles want to do, living in sensuality, passions, drunkenness, orgies, drinking parties, and lawless idolatry. With respect to this they are surprised when you do not join them in the same flood of debauchery, and they malign you; but they will give account to Him who is ready to judge the living and the dead. For this is why the Gospel is preached even to those who are dead, that though judged in the flesh the way people are, they might live in the spirit the way God does." - 1 Peter 3:14-22 - 1 Peter 4:1-6
Why would we suffer for righteousness? Because we have what? Answer: a good conscience.
We can suffer for righteousness sake because something has changed about us. We received something.
Christ suffered once for sin, He being righteous and all the rest of us unrighteous, that He might what? Answer: Bring us to God.
In the same way that God, in His grace and patience saved Noah and his family through water, there is an antitype to this water, and that's baptism, "which now saves you".
You chose to cling to an English translation here, "like figure unto" in order to try and bolster an idea that baptism "figures" or merely represents, symbolically, something. But that's not at all what the text says in the Greek.
The Greek word here is antitypos. Antitypos is literally the opposite of the Greek word typos, a typos ("type") is a figure, an impression--it's ultimately where we get "type" as in the block letters used in the moveable-type printing press. And referring to "type-faces" aka "fonts", and to the "type-writer", etc. And derived from this is also where we speak of a "type" of something, "that's my type of person" meaning an impression of an idealized person; or a "type" of something, a generalized figure of a thing, a class of something.
The waters of the flood are the typos, the antitypos is baptism. The antitypos is not the impression or "figure", but the opposite. If I paint a picture of someone, that picture is the typos, the person themselves is the antitypos.
Baptism, the antitypos, is not the impression, but the concrete thing itself; baptism is what the waters of the flood anticipate, point toward as the fuller and greater reality.
The ancient sacrifices of Israel are typos, Christ's sacrifice on the cross is the antitypos.
The Kohen Gadol (high priest) of Israel is the typos, Christ as the Great High Priest is the antitypos.
The Tabernacle/Temple in Jerusalem was the typos, Christ who was crucified and rose again and said "tear down this temple and in three days I will raise it up again" and about whom John in His Gospel writes, "The Word became flesh and tabernacled in our midst" is the antitypos.
The things of old are the typos, the new things in Christ are the antitypos.
Baptism is the antitypos, not the typos. It is through this antitype, which the work of God's saving Noah and his family through the waters of the flood ultimately points, that God does what? Even as He saved them He does what for us now? He saves us.
"Which now saves us", .
So Christ having suffered once for sin shows us the long-suffering patience of God, shows us how we too shall be patient. Not because we can, by our own power be like God. But rather because God who is long-suffering rescues us, reconciles us, and does what? Gives us a good conscience toward God.
A good conscience, a new conscience, by which we now no longer living as slaves to the passions of the flesh but alive unto God by the new life we have in Christ by His resurrection. This new conscience by which we, formerly disobedient and slaves to the passions, have a new obedience should be found patient, and giving answer to the hope that we have, being kind, gentle, respectful in all that we do. Suffering, if it is God's will, for the good that we do rather than evil. For those who malign us, who revile us, who slander us for being obedient to God, in suffering for God with patience, they will one day be judged--but we vindicated. Vindicated not because of our own righteousness, but vindicated in the righteousness of Jesus--He who suffered as the righteous for the unrighteous.
You weren't altogether wrong about the context, but you are still missing what is being said. You are overlooking the point, overlooking the GRACE of God.
Take a gander here at what Peter is saying in this part of his epistle. Look at it, and now look at what Paul says over in Romans chapter 6.
-CryptoLutheran