Rom 1:18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;
Rom 1:19 Because that which may be known of God is manifest in them; for God hath shewed it unto them.
Rom 1:20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse.
Creation testifies of a higher power and of His attributes which one of them is love for He provided food, and the means to make clothing and shelter, and testify of the 2 greatest laws love God and love people that applies throughout the history of mankind.
Rom 2:14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
Rom 2:15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another.
We have a conscience to be able to know right from wrong which is the law by nature.
Rev 20:12 And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.
Rev 20:13 And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works.
Rev 20:14 And death and hell were cast into the lake of fire. This is the second death.
Rev 20:15 And whosoever was not found written in the book of life was cast into the lake of fire.
People that have not heard of the word of God, and have not heard of Jesus will be judged by their belief in a higher power, and their love for people for love is the fulfilling of the law, and if there is anything amiss to ask God for forgiveness which they can be saved if they meet the criteria for God is not going to condemn people that have not heard of the word of God, and has not heard of Jesus.
But those saved cannot rule for a thousand years with Christ or be with Christ until the end of the millennial reign for they did not know Christ.
But an agnostic cannot be saved for they have doubt whether there is a God or not and that is not faith for they have to be sure that they believe that there is a higher power that wants them to love people.
Creation testifies that there is a higher power so a person cannot doubt whether there is a God or not.