"If the Father is so careful that all those who lived before Christ’s ascension into heaven & those who lived after His ascension would hear the gospel of salvation, then would He not provide an equal opportunity for fetuses & babies who were going to die young? 
At the moment of conception God joins the person’s spirit to the fertilized egg in the womb.
That embryo is now a human being. However the difficulty of being human even in the beginning of life is that the substance in which each spirit is housed, the human body, though very tiny, falls under the judgment of original sin (Ro 7:18). The law of sin, as Paul said, is in our flesh, our body primarily & in our soul.
He said, 'I see a different law in the members of my body…making me a prisoner of the law of sin which is in my members.' (Ro 7:23). 
The law of sin is inherited at conception & not the result of anything that we do or do not do.
In other words, we do NOT come under the law of original sin at the moment of birth but at the moment of conception.  David said, 'Behold, I was brought forth in iniquity, & in sin my mother conceived me.' (Ps 51:5).
This Scripture does not mean that the procreation of children is a sinful act. It means that once a human spirit has been joined to a fertilized egg, the fetus has the law of sin within it. Once we are under this law of sin, there are no means of salvation but through believing into Jesus Christ as Lord & Savior. 
How can a fetus or baby hear, understand & accept the gospel of salvation in Jesus Christ? You will recall that we said in Chapter 4 that the human spirit has all the faculties as the rest of the human being. It can hear, understand, decide & communicate (Rev 2:7; 1Co 2:12; Ac 19:21; 1Co 14:14-16). 
Jeremiah & David were called by God from the womb & responded to that call. Before I formed you in the womb I knew you, & before you were born I consecrated you. (Jer 1:5). You have been my God from my mother’s womb. (Ps 22:10). If Jeremiah & David could respond to God while in the womb, the Holy Spirit can likewise communicate the gospel to any child who will be aborted or miscarried or die in infancy. 
Why, we may ask, are not all human beings given the opportunity to choose Christ while they are in the womb? The reason is that the Lord wishes to give every person every opportunity to come to Him on earth & then to mature. Jesus charged His 12 disciples to go into all the world & make other disciples (Mt 28:19-20).
Although a life cut short does not exclude a baby from hearing the gospel & from choosing Christ, it does remove the opportunity for growth in discipleship while on earth. 
Those fetuses & infants choosing Christ are received into heaven at their death. 
The Father is just & more than just in turning the rebellion of Satan into an occasion for every person on earth in whatever circumstances to choose His Son as Savior & to live forever with God."