George Sodini is definitely a sad case. IDK what was in his heart, IDK whether he had a mental illness, etc. Truth be told, though, Paul makes it abundantly clear we cannot commit sin with impunity if we are saved:
Romans 6:1-23 NASB What shall we say then? Are we to continue in sin so that grace may increase? (2) May it never be! How shall we who died to sin still live in it? (3) Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death? (4) Therefore we have been buried with Him through baptism into death, so that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life. (5) For if we have become united with Him in the likeness of His death, certainly we shall also be in the likeness of His resurrection, (6) knowing this, that our old self was crucified with Him, in order that our body of sin might be done away with, so that we would no longer be slaves to sin; (7) for he who has died is freed from sin. (8) Now if we have died with Christ, we believe that we shall also live with Him, (9) knowing that Christ, having been raised from the dead, is never to die again; death no longer is master over Him. (10) For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. (11) Even so consider yourselves to be dead to sin, but alive to God in Christ Jesus. (12) Therefore do not let sin reign in your mortal body so that you obey its lusts, (13) and do not go on presenting the members of your body to sin as instruments of unrighteousness; but present yourselves to God as those alive from the dead, and your members as instruments of righteousness to God. (14) For sin shall not be master over you, for you are not under law but under grace. (15) What then? Shall we sin because we are not under law but under grace? May it never be! (16) Do you not know that when you present yourselves to someone as slaves for obedience, you are slaves of the one whom you obey, either of sin resulting in death, or of obedience resulting in righteousness? (17) But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed, (18) and having been freed from sin, you became slaves of righteousness. (19) I am speaking in human terms because of the weakness of your flesh. For just as you presented your members as slaves to impurity and to lawlessness, resulting in further lawlessness, so now present your members as slaves to righteousness, resulting in sanctification. (20) For when you were slaves of sin, you were free in regard to righteousness. (21) Therefore what benefit were you then deriving from the things of which you are now ashamed? For the outcome of those things is death. (22) But now having been freed from sin and enslaved to God, you derive your benefit, resulting in sanctification, and the outcome, eternal life. (23) For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
But Paul also makes it clear we are saved by grace through faith:
Romans 3:21-26 NASB But now apart from the Law the righteousness of God has been manifested, being witnessed by the Law and the Prophets, (22) even the righteousness of God through faith in Jesus Christ for all those who believe; for there is no distinction; (23) for all have sinned and fall short of the glory of God, (24) being justified as a gift by His grace through the redemption which is in Christ Jesus; (25) whom God displayed publicly as a propitiation in His blood through faith. This was to demonstrate His righteousness, because in the forbearance of God He passed over the sins previously committed; (26) for the demonstration, I say, of His righteousness at the present time, so that He would be just and the justifier of the one who has faith in Jesus.
and
Romans 4:1-8 NASB What then shall we say that Abraham, our forefather according to the flesh, has found? (2) For if Abraham was justified by works, he has something to boast about, but not before God. (3) For what does the Scripture say? "ABRAHAM BELIEVED GOD, AND IT WAS CREDITED TO HIM AS RIGHTEOUSNESS." (4) Now to the one who works, his wage is not credited as a favor, but as what is due. (5) But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness, (6) just as David also speaks of the blessing on the man to whom God credits righteousness apart from works: (7) "BLESSED ARE THOSE WHOSE LAWLESS DEEDS HAVE BEEN FORGIVEN, AND WHOSE SINS HAVE BEEN COVERED. (8) "BLESSED IS THE MAN WHOSE SIN THE LORD WILL NOT TAKE INTO ACCOUNT."
and
Romans 8:38-39 NASB For I am convinced that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, (39) nor height, nor depth, nor any other created thing, will be able to separate us from the love of God, which is in Christ Jesus our Lord.
and
Ephesians 1:3-14 NASB Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, (4) just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love (5) He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will, (6) to the praise of the glory of His grace, which He freely bestowed on us in the Beloved. (7) In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace (8) which He lavished on us. In all wisdom and insight (9) He made known to us the mystery of His will, according to His kind intention which He purposed in Him (10) with a view to an administration suitable to the fullness of the times, that is, the summing up of all things in Christ, things in the heavens and things on the earth. In Him (11) also we have obtained an inheritance, having been predestined according to His purpose who works all things after the counsel of His will, (12) to the end that we who were the first to hope in Christ would be to the praise of His glory. (13) In Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise, (14) who is given as a pledge of our inheritance, with a view to the redemption of God's own possession, to the praise of His glory.
and
Ephesians 2:4-10 NASB But God, being rich in mercy, because of His great love with which He loved us, (5) even when we were dead in our transgressions, 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 ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. (8) For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; (9) not as 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 so that we would walk in them.
I could go on, but I think my point is made. We are saved by God's grace accessed through faith (that inevitably leads to works).
What about the forgiveness of sins?
Ephesians 4:32 NASB Be kind to one another, tender-hearted, forgiving each other, just as God in Christ also has forgiven you.
Note that we are called to be kind to each other over current and future faults, just as God has forgiven us in like manner.
Colossians 2:13 NASB When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions,
The Ultimate Cross Reference Treasury has this to say on the bolded part:
The specification of "all" includes past, present, and future trespasses. This follows logically from the fact that justification does not admit of repetition, and that the pardon granted in justification "involves the removal of all guilt and of every penalty" (L. Berkhof, Systematic Theology, p. 514). Confession of sin for the believer does not restore him to salvation, but to fellowship with God (1Jn_1:9). If continued salvation depended upon complete confession, then by this theory the failure to confess one sin through oversight would result in loss of salvation, which is contradictory to the possibility of assurance of salvation, our placement as sons and joint-heirship with Christ (Joh_1:12, Rom_8:17, +*Gal_4:5; +*Gal_4:7 note), and the close connection between (1) justification and glorification (+*Rom_8:29; +*Rom_8:30); (2) present suffering and future glory (Rom_8:17, 2Ti_2:12); (3) remission of sin and future inheritance (+*Act_26:18); (4) justification and hope of glory (Rom_5:1-2). %Psa_25:7; Psa_85:2; **Psa_103:3; **Psa_103:12, Isa_44:22, =Zec_3:4, +*Act_26:18, Rom_5:1-2, *2Co_5:19, *Heb_10:14, **1Jn_1:7.
Romans 8:2 NASB For the law of the Spirit of life in Christ Jesus has set you free from the law of sin and of death.
How could I be set free from the law of sin and death if every time I grievously sin I lose my salvation? I cannot accept it, sorry brother.
