Why is Lazarus regarded as Saint Lazarus? Why or how did he get this title?
The Lord never established any special title or office called “saint.” The term “saint” in the Bible simply refers to any believer in Jesus Christ. Simply, put all Christians are saints according to the Bible.
Eph. 2:18 for through Him we both have our access in one Spirit to the Father.
Eph. 2:19 So then you are no longer strangers and aliens, but you are fellow citizens with the saints, and are of God’s household,
Eph. 2:20 having been built on the foundation of the apostles and prophets, Christ Jesus Himself being the corner stone,
Eph. 2:21 in whom the whole building, being fitted together, is growing into a holy temple in the Lord,
Eph. 2:22 in whom you also are being built together into a dwelling of God in the Spirit.
Notice Paul addresses all those who are in Jesus Christ by faith as “saints” in verse 19. Therefore, Lazarus was a “saint” because he believed in Jesus Christ, just as every person who places their faith in Jesus Christ is also a saint. In fact, if you have trusted in Jesus Christ as your Savior, then you too are a saint.
On the other hand, the Catholic religion (which is not Christianity) uses the word “saint” in a very different, unbiblical way to confer special status to certain historical figures which Catholics view to be worthy of such attention. Catholics invented the practice of designating certain people as “saints” to support their false theology that teaches we must merit entrance to heaven through our good works. This is a false Gospel, because the Bible clearly teaches that faith alone brings a person eternal life:
Eph. 2:8 For by grace you have been saved through faith; and that not of yourselves, it is the gift of God;
Eph. 2:9 not as a result of works, so that no one may boast.
Contrary to the Bible, Catholics teach that we must do good works to merit Heaven, and Catholics invented the idea of supposedly “super Christians” who have done especially good works that merit Heaven. They call these people saints, but this a false teaching as well.
Please read the following article on the Catholic religion vs. true Christianity: Are Roman Catholics Truly Christian?