Doctrinally speaking, what exactly justifies and saves us? What is it - precisely - that atones for our sins?

SCRIPTURAL REFERENCES:

Romans 3:24 they are justified by his grace as a gift, through the redemption which is in Christ Jesus....

Romans 5:9 Since, therefore, we are now justified by his blood, much more shall we be saved by him from the wrath of God.

Hebrews 9:12 he entered once for all into the Holy Place, taking not the blood of goats and calves but his own blood, thus securing an eternal redemption.

Hebrews 9:14 how much more shall the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify your conscience from dead works to serve the living God.

Hebrews 10:4 For it is impossible that the blood of bulls and goats should take away sins.

Hebrews 10:29 How much worse punishment do you think will be deserved by the man who has spurned the Son of God, and profaned the blood of the covenant by which he was sanctified, and outraged the Spirit of grace?

First Peter 1:18 You know that you were ransomed from the futile ways inherited from your fathers, not with perishable things such as silver or gold,
First Peter 1:19 but with the precious blood of Christ, like that of a lamb without blemish or spot.

First John 1:7 but if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin.

From the Bible verses above, it is clear that we are justified, saved, forgiven, and atoned for simply by a phenomenon not of our own doing in the least, a shedding of the blood of Jesus crucified to death on some cross centuries ago in some distant location.....a lynching and murder we personally had nothing to do with. THAT is defined as: "the GOSPEL!"

Of THAT particular "gospel," Saint Paul wrote:

Galatians 1:8 But even if we, or an angel from heaven, should preach to you a gospel contrary to that which we preached to you, let him be accursed.
Galatians 1:9 As we have said before, so now I say again, If any one is preaching to you a gospel contrary to that which you received, let him be accursed.

"Accursed" is closely related to: "damned."

Now, what about salvation, justification, and atonement involving SINFUL-HUMAN endeavors and activities:

Romans 3:28 For we hold that a man is justified by [his or her own nonreliable and inconsistent] faith? apart from works of law.

Romans 5:1 Therefore, since we are justified by [his or her own nonreliable and inconsistent] faith?, we have peace with God through our Lord Jesus Christ.

Galatians 2:16 yet who know that a man is not justified by works of the law but through [his or her own nonreliable and inconsistent] faith? in Jesus Christ, even we have believed in Christ Jesus, in order to be justified by [his or her own] faith? in Christ, and not by works of the law, because by works of the law shall no one be justified.

James 2:24 You see that a man is justified by [his or her own nonreliable and inconsistent] works, and not by [his or her own] faith? alone.
James 2:25 And in the same way was not also Rahab the harlot justified by [her own nonreliable and inconsistent] works when she received the messengers and sent them out another way?

First Peter 3:21 [Your own self-initiated or human-parents-initiated] 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 clear conscience, through the resurrection of Jesus Christ...

When we speak of OUR faith, OUR works, OUR baptism and baptizing.....we speak of something other than the justifying, saving, and atoning which CHRIST HIMSELF did for US.....and all who presume that we are justified, saved, and atoned for by anything WE do for ourselves are ACCURSED and damnably guilty of despicable dishonesty and lying!

If there is any "justification by faith alone" or "justification by works, not faith alone," it is the faith alone and works not faith alone of Christ Jesus only, freely imparted to us by His merit and grace.

To summarize, we are not justified, saved, nor atoned for by allowed-to-murder jewish and roman murderers of time past.....but rather justified, saved, and atoned for by the allowed-Himself-to-be-murdered Murdered.