Christians have asked this question centuries. Even in today’s globalized, social-media-driven world, Christians are still asking it. In question 60 of the Westminster Larger Catechism, the question is posed: “Can they who have never heard the gospel, and so know not Jesus Christ, nor believe in him, be saved by their living according to the light of nature?” Here is its answer:
They who, having never heard the gospel, know not Jesus Christ, and believe not in him, cannot be saved, be they never so diligent to frame their lives according to the light of nature, or the laws of that religion which they profess; neither is there salvation in any other, but in Christ alone, who is the Savior only of his body the church.
It is true that there is salvation in no other name than Jesus (Acts 4:12). To be saved means to confess with your mouth that Jesus is Lord and believe that he is risen from the dead (Rom. 10:9). God is sovereign and he saves those whom he wills (see Rom. 9:19-24; John 6:44; 10:25-28; Eph. 2:8-9). The unsaved are non-elect, and therefore, those who have not heard are not elect. Furthermore, people are condemned because they are guilty sinners (6:23). We must remember that there are no innocent people in the world (Rom. 2:12-16; 3:10-23).
How could this be, you ask, when a person in the jungles of Africa does not even know God exists? John Calvin helps us understand: “Since, then, there never has been, from the very first, any quarter of the globe, any city, any household even, without religion, this amounts to a tacit confession, that a sense of deity is inscribed on every heart. No, even idolatry is ample evidence of this fact.” (Institutes 1.3.1).
God promises there will be a multitude from every tribe, language, people, and nation who were ransomed by the blood of the Lamb and who will reign with him forever (Rev. 5:9-10). So rather than raising a finger at God for what is clearly taught in Scripture, we must resolve to spread the gospel across this earth, making disciples of all nations (Matt. 28:19-20). That might mean leaving all you have to be a frontier missionary. It might mean giving more (yes, more) money to missions. It will definitely mean praying often for unreached peoples. In all you do, remember to rest in the truth that God will bring all his sheep into one fold under the care and provision of their one, good Shepherd, Jesus Christ (John 10:16). cit confession, that a sense of deity is inscribed on every heart. No, even idolatry is ample evidence to this fact” (Institutes 1.3.1). There is a sense in every person that God exists. and the very fact that we worship something proves it.
To hear a little more on this, listen to a two minute audio clip to from John Piper.