Luther was a prolific writer, and the errors below are likely due to the author reading less of Luther than even i have, who was yet too Catholic to be any kind of pope for us, though we honor him for the right stands he took against the Roman church, whose distinctives are no manifest in the only inspired record of the NT church , and contrary to it.
This act of faith in and of itself does not justify man, but rather disposes him for justification. The soul is brought into a state of justification (i.e., friendship with God) through an infusion of sanctifying grace and supernatural charity into the soul, which produces a true spiritual rebirth (a metaphysical change in the soul) and makes man a partaker of the divine nature (2 Peter 1:4), an adopted child of God (Eph. 1:5), and an heir of heaven (Romans 8:17).
What this Catholic conception teaches is not that "to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness, " (Romans 4:5) that "to him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sin s," (Acts 10:43) "purifying their hearts by faith " (Acts 15:9)
Instead what this Catholic contrivance teaches is that one is made actually good enough to be with God through the sprinkling of water, that of infused charity via the actual act of RC baptism, which means Abraham must have become born again when his faith was counted/imputed for righteousness.
Moreover, since the process of Catholic salvation begins with actually becoming good enough to be with God, then since souls usually do not maintain or regain this condition by the time they die, then this false gospel requires the invention of RC (different in the EOs version of tradition) Purgatory, in which it is imagined that one is purified of character defects thru "purifying torments" (and atones for sins).
In contrast, God justifies the ungodly by imputing his faith for righteousness, purifying their hearts by faith, (Romans 4:5; Acts 15:9) a faith that is expressed in baptism and obeying the Lord Jesus, but who are "accepted in the Beloved" and "made to sit together with Him" in Heaven, (Eph. 1:6;2:6) having immediate access into the holy of holies in Heaven by the blood of Christ. (Heb. 10:19)
And thus wherever Scripture clearly speak of the next conscious reality for believers then it is with the Lord, (Lk. 23:43 [cf. 2Cor. 12:4; Rv. 2:7]; Phil 1:23; 2Cor. 5:8 [we]; 1Cor. 15:51ff'; 1Thess. 4:17) Note in the latter case all believers were assured that if the Lord returned, which they expected in their lifetime, so would they ever be with the Lord, though they were still undergoing growth in grace, as was Paul. (Phil. 3:10f)
And the next transformative experience that is manifestly taught is that of being like Christ in the resurrection. (1Jn. 3:2; Rm. 8:23; 1Co 15:53,54; 2Co. 2-4) At which time is the only suffering after this life, that of the loss of rewards due to the combustible nature of the material one built the church with, which one is saved despite of, not because of. (1Co. 3:8ff)< /p>
Error # 2
Luthers errors concerning salvation are founded on an entirely different understanding of the words faith, justification, and grace. The act of faith, according to Luther, is not an intellectual assent to the truths revealed by God, but rather trust in divine mercy, combined with a firm conviction that one has received Gods favor and will be saved. This notion of faith is not rooted in the intellect (believing what God has revealed), but in the will (trusting in Christ),
This seems desperate, for intellectual assent is certainly not salvific, as even devils believe, while Luther certainly knew that faith in the heart is the root that effects repentance, though they are inseparable, two sides of the same coin.
For Christian righteousness consisteth in two things; that is to say, in faith of the heart, and in God's imputation.. ― John Dillenberger - 2011, "Martin Luther: Selections From His Writing" p. 127
Justification: Merely Declared Righteousness According to Luther, the justified soul is not made just, nor are his sins truly washed way. Luther taught that the act of justification consist of an extrinsic imputation of the justice of Christ, by which the believer is only declared just by God (i.e., declared righteousness), rather than an intrinsic infusion of grace into the human soul and a true washing away of sin, by which one is truly made just.
This description in which there is no purifying of the soul under salvation by faith is the type of thing you read from Catholic Answers, and is not Biblical nor consistent with what Luther taught:
"..He Himself dwell in us and through us on account on such faith, and daily purifies us through His own work..." "Hence it is clearly evident that purification for sins, is faith, and he that believes that Christ has purged his sins, is most assuredly purified through that faith, and in no other way." - Explanation of the epistle for Christmas, Concerning the divinity of Christ, in "Dr. Martin Luther's Church-postil: Sermons..."edited by Socrates Henkep. 93
Later (apparently) Luther taught this faith is effectual via baptism (even for infants, which is false):
"when any one is washed with water, after the command of Christ, he is washed with the blood of the Lord Jesus Christ, and cleansed from all sins." - Henkep, p. 18
"This does not happen by a change of clothing, or by any laws or works; it happens by the rebirth and renewal that takes place in Baptism, as Paul says, 'As many of you as were baptized have put on Christ."' lectures on Galatians 1531
For in those who have been baptized a new light and flame arise; new and devout emotions come into being, such as fear and trust in God and hope; and a new will emerges. This is what it means to put on Christ properly, truly, according to the Gospel."
Of course we are well aware that baptism is natural water. But after the Holy Spirit is added to it, we have more than mere water. It becomes a veritable bath of regeneration, a living bath which washes and purges man of sin and death, which 'cleanses him of all sin." (Sermons On The Gospel Of St. John, Chapters 1 ‑4.1537.)
It is of course true that nothing in us does it except faith, as we shall hear later. But these blind leaders of the blind refuse to see that faith must have something in which it believes, that is, something it clings to, something on which to plant its feet and into which to sink its roots. Thus faith clings to the water and believes Baptism to be something in which there is pure salvation and life, not through the water, as I have emphasized often enough, but because Gods name is joined to it It follows from this that whoever rejects Baptism rejects Gods word, faith, and the Christ who directs us to Baptism and binds us to it (1978, pp. 101-102). (Taken From Luthers Large Catechism (XIII))
Holy Baptism is the only means whereby infants, who, too, must be born again, can ordinarily be regenerated and brought to faith (Luthers Small Catechism, 16, 173).
When we become Christians, the old creature daily decreases until finally destroyed. This is what it means truly to plunge into baptism and daily to come forth again." (see Small Catechism, 360:12; KK, 884:1415)
"...though the Holy Spirit renews our hearts but yet in such a manner, that he does not at once complete this work of our renewal and purification, but He operates and purges in us daily, until we become continually more and more pure...though the office of the word..." - Henkep, p. 95
Luthers Errors Concerning Grace Along with his erroneous understanding of faith and justification, Luther had an equally erroneous understanding of grace. Since he denied that the soul was interiorly transformed and regenerated by the Holy Ghost,...In short, Luthers doctrine of justification and salvation goes like this: man makes an act of faith (places his trust in the merits of Christ); the justice of Christ is imputed to him and covers over his sinfulness, without actually changing him within;
Which is lie #3, for Luther believed the soul was interiorly transformed and regenerated by the Holy Ghost, which happens in conversion and is not contrary to being justified by imputed righteousness, with that being the cause of acceptance with God, on Christ's account, and not by actually becoming good enough to be with God as per Rome. Yet regeneration is salvific in the sense of sanctification, saving one from the power of sin, versus only its penalty. (Titus 2:11-12; 3:5)
I do not have the energy today (being up most of the night due to a mech. failure) to go thru the rest, save for the last lies:
The false doctrine of once saved always saved is based on Luthers error that Christs merits cover over the sinful soul (like snow covering a dunghill), and will remain even if they commit a thousand murders and a thousand adulteries per day.
Actually Luther clearly taught (despite hyperbolic argumentation Caths abuse) that saving faith is an obedient faith, such as in saying,
"...one says: Yes, I will now believe, and then he goes and fabricates for himself a fictitious delusion, which hovers only on the lips as the foam on the water. No, no; faith is a living and an essential thing, which makes a new creature of man, changes his spirit and wholly and completely converts him. It goes to the foundation and there accomplishes a renewal of the entire man; so, if I have previously seen a sinner, I now see in his changed conduct, manner and life, that he believes. So high and great a thing is faith.[Sermons of Martin Luther 2.2:341]
This is where we get the Protestant practice of altar calls and repeating the sinners prayer - neither of which are found in the Bible, or anywhere else for the first 1500 years of Christianity.
An altar call is essentially calling convicted souls to make a definite decision for Christ, which Peter did in Acts 2, and a sinners prayer is essentially doing the same thing as the penitent publican (Lk. 18) and the contrite criminal did (Lk. 23) in calling upon the Lord to have mercy on them as damned destitute sinners in faith.