A stumbling block many people have in their faith towards God has to do with the question of the fate of the billions who have lived without having an opportunity to know God or to learn about Jesus Christ. Many people have been taught that the billions who have lived and died without having the opportunity to become Christians are doomed to condemnation and will never be saved. This idea makes it seem to many that God is either unfair or is powerless to prevent this.
The Bible is clear that salvation is possible only through Jesus Christ (Acts 4:9-12). And it is clear from history that most of the billions of people on the earth have never had the opportunity to learn the truth about Christ, both those who have lived before Christ was born, and those who are alive today in countries where true Christian teaching is not widely available.
Are these people condemned to the permanent loss of salvation?
Many people think this is the case. And if true, this seems to indicate to the minds of many that either God is unfair to allow this, or that God is not powerful enough to prevent it.
But God is not unfair or powerless. Every human being who has ever lived will have the opportunity for salvation. No one will be left out.
Part of the answer is given in Ezekiel chapter 37. This is also the time known as the great white throne judgment described in Revelation 20:11-15. This is a time, yet future, when all who have ever lived without an opportunity for salvation in this life will be resurrected back to physical life. At that time, they will have their first real opportunity for salvation. Everyone will be given time to live and make their choice. Those who repent and have faith in God and Christ will be given immortality in the Kingdom of God. Those who reject God and Christ will not be saved. See The Last Great Day - the White Throne Judgment for more details.