Salvation has been given to mankind from Adam and Eve to the last person born on this planet.
People that have not heard of Jesus and the word of God still can be saved for God is a fair God.
The Bible testifies that there is a God that created everything, and of His attributes which one of them is love for He provided food, and the means to make clothing and shelter, so the world is without excuse, and covers the 2 greatest laws, love God and love people, which is what a Christian goes by.
Our conscience bears witness of what is right and wrong.
People that have not heard of Jesus and the word of God will be judged on their belief in a higher power, and their love towards people, which love works no ill towards their neighbor, therefore love is the fulfilling of the law.
If they abide by love God, and love people not offending them, and ask God for anything that is amiss for they do not have words from Him, and have not heard from Him they can be saved after the millennial reign of Christ, and join the saints.
They cannot dwell with Jesus now for they did not know of Jesus and the word of God, but after the millennial reign they can dwell with Jesus, and join the saints for they went by the 2 greatest laws love God, and love people.
God is a fair God and will not condemn people because they have not heard the truth of Jesus and the word of God, but creation testifies of the 2 greatest laws, love God and love people, and their conscience knows right and wrong, and that it is wrong to offend people.
If the people that have not heard of Jesus and the word of God abide by the truth of love God, and love people by not offending them, they can be saved after the millennial reign of Christ.
Of course a saint has the advantage having the word of God, which the Bible says that Israel had the advantage for the words of God were given to them, which makes it easier to believe.
Rom 2:13 (For not the hearers of the law are just before God, but the doers of the law shall be justified.
Rom 2:14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
Rom 2:15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another)
Rom 2:16 In the day when God shall judge the secrets of men by Jesus Christ according to my gospel.
If all people that have ever lived shall be judged then all people that have ever lived can receive salvation at any time period, for if they did not hear of Jesus and the word of God why are they judged when it is not their fault, and if they are judged then salvation is available to them if they have not heard of Jesus and the word of God if they go by the 2 greatest commandments, love God, and love people.
Act 10:34 Then Peter opened his mouth, and said, Of a truth I perceive that God is no respecter of persons:
Act 10:35 But in every nation he that feareth him, and worketh righteousness, is accepted with him.