Romans 5:13
(For until the law sin was in the world: but sin is not imputed when there is no law.
People can't sin until they learn the law. If you never hear the gospel, you never learn the law. Therefore, if you never hear the gospel you can't sin.
That verse is referring to a time before Moses came and received the 10 Commandments,but the law is here and is on the heart of every man.
I am sorry you have that misconception ,
Rom 6:23but For the wages of sin [is] death; but the gift of God [is] eternal life through Jesus Christ our Lord.
The problem is that the law is not on tablets anymore but ingraved on the heart and the mind
Hbr 8:10For this [is] the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people:
Rom 5:12Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:
The only way a man can neeter heaven is through Christ by the Holy Spirit
Jhn 1:12 But as many as received him, to them gave he power to become the sons of God, [even] to them that believe on his name:Which were born,
not of blood,
nor of the will of the flesh, nor of the will of man,
but of God.
Regardless of the law you will be perish if you do not receive Christ as the full payment of sins
Rom 2:12For as many as have sinned without law shall also perish without law: and as many as have sinned in the law shall be judged by the law;
If all you have is nature and still don't turn to God you will be condemned
Rom 1:20For since the creation of the world His invisible
attributes are clearly seen, being understood by the things that are made,
even His eternal power and Godhead, so that they are without excuse,