For since in the wisdom of God the world through its wisdom did not know him, God was pleased through the foolishness of what was preached to save those who believe.[1 Cor. 1:21]
The preaching of God's word is what God chose to use to save ppl from their sins.
How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? And how can anyone preach unless they are sent? As it is written: “How beautiful are the feet of those who bring good news!”[SUP] [/SUP]But not all the Israelites accepted the good news. For Isaiah says, “Lord, who has believed our message?”[SUP] [/SUP]Consequently, faith comes from hearing the message, and the message is heard through the word about Christ.[Romans 10:14-17]
As Paul wrote, "how can they believe in the One whom they have not heard? And how can they hear w/o someone preaching to them? Natural revelation is not preaching to them. It takes the word of God, not nature, to bring one to saving faith.
And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit,[Eph. 1:13]
It is only after one has heard the word of the God, that they can be saved. Nature does not attest to the gospel of the Christ.