The above question to Jesus is slanted by the use of the word "few." Today the question would be re-slanted: "Lord, isn't almost everyone going to heaven?" Jesus answered the original question not by saying that only a few people will be saved, but He certainly gives us no reason to presume that almost everyone will be saved. Jesus "replied, 'Try to come in through the narrow door. Many, I tell you, will try to enter and be unable' " (Lk 13:24). This seems to imply that many people are in hell.
However, Jesus wills everyone "to be saved and come to know the truth" (1 Tm 2:4). Jesus' saving death was not in vain. Jesus has changed and will change the hardest hearts. Because of His grace, love, and mercy, we can have a "blessed assurance" of our salvation despite our resistance to repentance and conversion. Nonetheless, there is no such thing as "blessed presumption."
We can "be in that number" of heavenly saints by living our Baptisms. This means we reject Satan completely and love the Father, the Son, and the Holy Spirit with all our hearts, all our souls, all our minds, and all our strength (Lk 10:27). Right now, accept Jesus as Lord, Savior, and God on His terms. Give yourself totally to the Lord. Be saved.