Sin is the disobeying of God’s commandments.
The Bible tells us that God hates sin.
When we reach the age of responsibility, we all become sinners.
Romans 3:23 For all have sinned, and come short of the glory of God;
Romans 5:12 Wherefore, 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:
God demonstrated his love for us (sinners) in providing his Son to sacrifice his life in order to redeem us from sin and death.
Romans 5:8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.
1 John 4:10 Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins.
Therefore, we conclude that God loves sinners enough to make the effort to save them.
We nonetheless have free choice and must make a choice.
Through his prophets and his Son and his apostles, God pleads with sinners to repent and turn to him.
The onus is upon us to believe and obey.
Children who die before they reach the age of responsibility, die, not because they are sinners, but because they have Adam’s mortal nature.
Salvation is only possible for those who understand, believe and obey the gospel.
John 20:31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
I hope you find this helpful.