How will God hold accountable those who were born into a non-observant environment or to non-Muslim parents in Western countries, and can we definitively determine how He will judge them, or is their matter up to God?

A believer should repel doubts by holding fast to the established fundamentals of his creed. Allah Almighty is characterized by justice, wisdom, compassion, and mercy, which are irrefutable principles that no believer doubts. Guidance is a blessing from Allah, which He places by His wisdom where it belongs. He guides whom He wills out of grace and mercy, and He misleads whom He wills out of wisdom and justice. Environment, upbringing, and family are not the sole factors in righteousness; rather, this is attributed to Allah's justice and wisdom. Allah does not punish anyone except after the establishment of proof (Hujjah) by the clear communication of the Islamic call in a way that one can understand. The establishment of proof differs according to times, places, and individuals. Punishment is deserved due to turning away from the proof or obstinacy towards it after its establishment. As for one who dies upon a religion other than Islam, and the call did not reach him properly, his ultimate fate in the Hereafter is a matter of scholarly disagreement.