What does Jesus mean by :
Matthew 19:14 14 But Jesus said, Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven.
Does he mean by this that children enter heaven no matter what because they have not come to the age of accountability or they have not yet been fully made aware of sin, similarly to have Adam and Eve had yet not eaten of the tree of knowledge of good and evil so they had not yet become aware of sin. Just like a small child is not aware of the concept of sin but rather trusts his father and mother.
What about :
(Romans 7:9 [KJV]) For I was alive without the law once: but when the commandment came, sin revived, and I died.
Does this mean that Paul was saved as a child when he didn't know about sin and the law and then when he grew up he became aware of sin and therefore would have ended up in hell if he had died then. As a grown up he eventually was saved on the road to Damascus.
No I would say this is not the true interpretation of these verses.
Look at this verse :
(Proverbs 20:11 [KJV]) Even a child is known by his doings, whether his work be pure, and whether it be right.
Here we can see clearly that children can be lost.
Also the idea that Paul was once saved as a child, then lost his salvation when he grew up and then got saved again on the road to Damascus. This idea sounds incorrect.
The truth is that we have to interpret Jesus statement in Matthew 19:14 differently for doctrine to fall into place correctly.
What Jesus is talking about in Mt 19:14 is childlike faith in my opinion. He is using the children as an illustration of childlike faith in God the Father.
Similarly to have small children have total trust in their parents. Similarly we should have the same kind of faith in God the Father as children of God.
(II Corinthians 6:14-18 [KJV])  Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?  And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?  And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people.  Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you,  And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
Like in this scripture. If we just have childlike faith, that is just trust what the scripture says then God the Father in heaven will be a Father unto us (II Corinthians 6:18).