No need to reconcile. Romans is a general statement while 1 John gives specific distinction. Again, you cannot ignore what John clearly writes just because it does not fit with your pre-conceived theology. In 1 John the Bible clearly states that there is a distinction between deadly/mortal sins and those that are not.
No need to reconcile.
Perhaps I should have posted a bit more.
1Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ, 2through whom also we have obtained our introduction by faith into this grace in which we stand; and we exult in hope of the glory of God. 3And not only this, but we also exult in our tribulations, knowing that tribulation brings about perseverance; 4and perseverance, proven character; and proven character, hope; 5and hope does not disappoint, because the love of God has been poured out within our hearts through the Holy Spirit who was given to us.
6For while we were still helpless, at the right time Christ died for the ungodly. 7For one will hardly die for a righteous man; though perhaps for the good man someone would dare even to die. 8But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. 9Much more then, having now been justified by His blood, we shall be saved from the wrath of God through Him. 10For if while we were enemies we were reconciled to God through the death of His Son, much more, having been reconciled, we shall be saved by His life. 11And not only this, but we also exult in God through our Lord Jesus Christ, through whom we have now received the reconciliation.
12Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned— 13for until the Law sin was in the world, but sin is not imputed when there is no law. 14Nevertheless death reigned from Adam until Moses, even over those who had not sinned in the likeness of the offense of Adam, who is a type of Him who was to come.
15But the free gift is not like the transgression. For if by the transgression of the one the many died, much more did the grace of God and the gift by the grace of the one Man, Jesus Christ, abound to the many. 16The gift is not like that which came through the one who sinned; for on the one hand the judgment arose from one transgression resulting in condemnation, but on the other hand the free gift arose from many transgressions resulting in justification. 17For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ.
18So then as through one transgression there resulted condemnation to all men, even so through one act of righteousness there resulted justification of life to all men. 19For as through the one man’s disobedience the many were made sinners, even so through the obedience of the One the many will be made righteous. 20The Law came in so that the transgression would increase; but where sin increased, grace abounded all the more, 21so that, as sin reigned in death, even so grace would reign through righteousness to eternal life through Jesus Christ our Lord. Romans 5
1What shall we say then? Are we to continue in sin so that grace may increase? 2May it never be! How shall we who died to sin still live in it? 3Or do you not know that all of us who have been baptized into Christ Jesus have been baptized into His death? 4Therefore 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. 5For if we have become united with Him in the likeness of His death, certainly we shall also be in the likeness of His resurrection, 6knowing 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; 7for he who has died is freed from sin.
8Now if we have died with Christ, we believe that we shall also live with Him, 9knowing that Christ, having been raised from the dead, is never to die again; death no longer is master over Him. 10For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. 11Even so consider yourselves to be dead to sin, but alive to God in Christ Jesus.
12Therefore do not let sin reign in your mortal body so that you obey its lusts, 13and 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. 14For sin shall not be master over you, for you are not under law but under grace.
15What then? Shall we sin because we are not under law but under grace? May it never be! 16Do 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? 17But 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, 18and having been freed from sin, you became slaves of righteousness. 19I 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.
20For when you were slaves of sin, you were free in regard to righteousness. 21Therefore what benefit were you then deriving from the things of which you are now ashamed? For the outcome of those things is death. 22But now having been freed from sin and enslaved to God, you derive your benefit, resulting in sanctification, and the outcome, eternal life. 23For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
Romans 5-6 NASB
http://www.saintaquinas.com/mortal_sin.html
The Roman Catholic requirement for a mortal sin:
Mortal sin is a sin of grave matter
Mortal sin is committed with full knowledge of the sinner
Mortal sin is committed with deliberate consent of the sinner
Except these conditions are not noted in the NT. They've been added by Rome.
These contradict Ephesians 2:1-2 where Paul notes:
1And you were dead in your trespasses and sins,
The word for trespasses is 3900 paráptōma (from 3895 /parapíptō, see there) – properly, fall away after being close-beside, i.e. a lapse (deviation) from the truth; an error, "slip up"; wrong doing that can be (relatively) unconscious, "non-deliberate."
It covers all of the things we do we are not even aware of.
But let's review just a couple of the "mortal sins".
Idolatry—Idolatry is the worship, veneration or belief in false gods. Because it is a direct rejection of God, it is a grave sin (1 Corinthians 6:9-10). Idolatry includes worship of images (This does not mean that we cannot venerate religious images. Veneration of images such as a crucifix is veneration of the person depicted, and not the actual image in and of itself.)
Rome has to add this to get around all of the idols of Mary and the worship of Mary.
Divination, magic and sorcery—This is a grave sin which includes attempting to command the powers of the occult, control or speak to demons or spirits (especially Satan), attempting to divine the future, and the use of magic charms (CCC 2116). Deuteronomy 18:10-11 speaks against this grave sin.
Do you wear the Brown or Green Scapular...or perhaps the Miraculous Medal?
Several of your fellow Roman Catholics have admitted they do.
What's worse is that Rome itself allows this. What does this say about Roman Catholicism?
Gluttony—Gluttony is an excessive love for food, and is a disordered passion for wordly appetites. Because it is contrary to the virtue of temperance, it can constitute a grave sin. Gluttony is also a capital sin (CCC 1866, 2290)
How many overweight Roman Catholics are there? Ever pig out at Thanksgiving? Christmas? Do you confess that?
Divorce—The grave sin of divorce condemns those who divorce and remarry (Matthew 5:32) and those who divorce in the civil sense (except by grave dispensation). Hence divorce between two baptized Christians is a mortal sin (CCC 2384). How many divorced Roman Catholics are there? Forget the appeal to annulment as that isn't in the NT.
Adultery—Adultery is marital infidelity. A married person who has sexual relations with anyone but their lawful spouse, even transient sexual relations, commits adultery (CCC 2380).
Ever look at a woman with lust? If any dude says no they've committed yet another sin.
Murder (intentional homicide)—Direct and intentional killing is gravely sinful (CCC 2268). It is a sin that cries to heaven for vengeance, much like the murder of Abel at the hands of Cain. Indirect homicide can also be of grave nature (such as refusing to help a person in danger). However, the Church teaches that self-defense is permissible for the preservation of a one’s life. If the attacker is mortally wounded or killed, then the death of the attacker is not a sin. Those who use unnecessary aggression in self-defense can sin mortally, if the attacker is killed or gravely injured.
Ever been so mad at someone you wanted them dead? Be honest...if you're not that's another mortal sin. Jesus equated the thought of murder as having done the act.
Pornography—Pornography is the display of intimate real or simulated sexual acts to a third party. Because it removes the marriage act from within the sacramental sanctity of marriage, and perverts sex, it is gravely contrary to charity (CCC 2354). The display of pornography to children and other parties is especially gravely sinful because it is gravely scandalous.
Most are probably equating this with XXX rated type movies. But I'd say if you've seen a movie...any movie...with this it's pornography. That's gonna be a whole bunch of movies.
Theft—All persons have a right to lawful private property obtained by legitimate work, inheritance or gift. To violate a person’s right to property by theft is a grave sin, especially if the loss of the property will severely hurt the victim (CCC 2408). The gravity of theft is determined by the harm it does to the victim. A poor beggar who steals a loaf of bread commits a less grave sin than a rich man who steals the savings of a destitute person. St. Paul tells us that thieves shall not inherit the kingdom of God (1 Corinthians 6:9-10).
Ever take a pen from work? Maybe a sheet of paper?
Cheating –A cheater defrauds his victim of their property. It is morally of grave matter unless the damage to the victim is unusually light (CCC 2413).
Ever goof off at work....or maybe slip in or out a little late or early? Ever exceed the speed limit by even 1 mph?
Lying—Lying is the most direct offense against the truth. It is gravely sinful when it significantly degrades the truth. The gravity of this sin is measured by the truth it perverts, the circumstances, intentions of the liar and harm done to the victims (CCC 2484). Lying is a sin that originates from the devil, Satan, who is "the father of all lies" (John 8:44).
Ever tell a "little white lie"? If your wife asks, "does this dress make me look fat?"....what say you? Be honest!
Incredulity, heresy, apostasy, schism,—Incredulity is the neglect of revealed truth or willful refusal to assent to it. Heresy is obstinate post-baptismal denial of a truth that must be believed with divine and catholic faith. Apostasy is total repudiation of the Christian faith. Schism is the refusal of submission to the Roman Pontiff or communion with the members of the Church (CCC 2089). These sins strain or break the bonds of unity with the offender and the Catholic Church.
Wow CCC 2089...this one is going to get a lot of Roman Catholics who hate Francis.
I've seen several Roman Catholics dismiss Unam Sanctam because they don't like Francis.
Avarice—Avarice is greed and the desire to amass earthly goods without limit. It is a passion for riches and luxury. Those who seek temporal happiness at the expense of spiritual duties, risk the grave sin of avarice. Avarice is one of the deadly vices (CCC 2536).
Envy—Envy, another capital sin, is sadness at the sight of another’s goods and the immoderate desire to acquire them for oneself. Envy can lead to grave consequences and can harm neighbors. If envy leads to grave harm to a neighbor, it is surely a grave sin.
I put those two together as they seem to go hand in hand?
Got a 401k? Ever check the balance and wish it were higher...or did you perhaps despair during the late market turndown? Have or want a newer car? Do you trade on a regular basis? Perhaps you want a bigger house....or a better kitchen? Ever see your neighbor's house and wish you perhaps had his/hers?
Do you tithe to God? Or do you withhold money because you don't like what's happening in your church? I've seen a number of Roman Catholics urge not contributing until things change in the RCC.
Hatred—Hatred of a neighbor is to deliberately wish him evil, and is thus a grave sin (CCC 2303 and Galatians 5:19-20).
This is going to nail a lot of Roman Catholics who hate us non-Roman Catholics.
This is just a partial listing.
If Roman Catholics are honest....most of these are committed everyday.
It's why Paul wrote....all have sinned and fall short of the glory of God.....and that the wages of sin is death.
Apart from faith in Christ and His forgiveness all of us are condemned to death and Hell...for all of our sins.