The Twelve asked Jesus this question (Luke 13.23).
His answer is surprising, in that He said that some who might be expected to be saved are not. Others (Gentiles) will come from the east and west and north and south and will enjoy the eternal kingdom of God.
The New Testament answers the same question with the word ‘many.’ The number who will enjoy God’s eternal kingdom will be huge.
Paul uses this word in Romans 5.15, 19:
“But the gift is not like the trespass. For if the many died by the trespass of the one man, how much more did God’s grace and the gift that came by the grace of the one man, Jesus Christ, overflow to the many! … For just as through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous.”
John’s visions in Revelation tell a similar story. The apostle is transported in space and time, we might say. At times he looks back from the far future. He sees a great multitude that no-one can count (Rev 7.9). These are those who are ‘saved.’
Sometimes we hear a teaching that suggests that very few will be saved, that Heaven will be sparsely populated. These verses seem not to reach that same conclusion.
Back to Paul. He boldly states: “”Be glad, O barren woman, who bears no children, break forth and cry aloud, you who have no labour pains; because more are the children of the desolate women than of her who has no husband.” This is Gal 4.27, quoting Gen 21.10. He is referring to the children of Sarah, but says that we are also like Isaac, children of promise. Could it be that more will be saved than lost?
In bringing the Twelve some reassurance, Jesus told them that He is going to prepare a place for them (John 14.2-3). The Greek word (MONE) is a dwelling place. Apparently, our English words ‘manor’ and ‘manse’ are derived from this word. Heaven, it seems, will be full but not crowded. We will be able to truly enjoy God in a spacious place (Psalm 18.9).