A Child Not Believing ‘Rightly’ Will Perish

Innocent ChildA Calvinist pastor from a church I used to attend put this comment up on Facebook:

“If a child doesn’t believe rightly in the true Jesus, he or she will perish eternally. In other words, right Christology is kind of important.”

The question that immediately popped into my mind was whether there’s an “age of accountability” before God sends a youngster to Hell? And, asking the next logical extension, would God send a ‘pre-born’ child which dies in the womb before physical birth to Hell because that child didn’t ‘believe rightly in the true Jesus’?
I commented and asked about a child’s age of accountability. Shortly thereafter, this pastor commented back saying,

“[Regarding] your question, it depends on each individual. [My wife] called on the Lord as an 8-year-old. I was 22. I know a man who was in his 60s. [My wife] and I labored to teach God’s word to our children beginning when they were toddlers.”

The question is about an age of accountability and a child’s inability to even know if they believe “in the true Jesus”. And the response is; “it depends on each individual.” Perhaps to a Calvinist, that makes sense. I understand that the Calvinist argument according to TULIP is that we’re all totally depraved and one’s ‘election’ unto salvation isn’t according to anything the individual has done – or has not done in the case of an aborted baby. As such, to the Calvinist, grace and mercy are meted out per God’s desire. Some get saved. But the reality is, most don’t. I simply cannot logically resolve the construct that Calvinists must therefore accept that God damns children who’re innocent of any sin? Seriously!? GOD KILLS KIDS FOR HIS GLORY!!?? Am I missing something? To my Calvinist friends who know I struggle with matters of faith – you want me to believe that God is holy, just and righteous. However, what is to be understood and what is implied in the nature and character of God that he, I presume from the foundation of the world, damns individuals who have not sinned and therefore aren’t needing Christ’s atonement?