The foundation is Jesus; it speaks of building upon it. Non-believers are not building upon the foundation of Jesus, so does this verse still apply to them?
Of coarse it does. To say that Jesus is the savior of anything LESS than ALL, lessens his sacrifice.
"For the CREATURE was made subject to vanity, not willingly, but by reason of him who hath subjected the same in hope, Because the CREATURE ITSELF also SHALL BE DELIVERED from the bondage of corruption into the glorious liberty of the children of God. For we know that the WHOLE CREATION groaneth and travaileth in pain together until now. And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body." Rom 8:20-23
"But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation." Rom 10:8-10
Now....read the next.
"For none of us liveth to himself, and no man dieth to himself. For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord's. For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living. But why dost thou judge thy brother? or why dost thou set at nought thy brother? for we shall ALL STAND BEFORE THE JUDGEMENT SEAT OF CHRIST. For it is written, AS I LIVE, saith the Lord, EVERY KNEE SHALL BOW to me, and EVERY TONGE SHALL CONFESS to God." Rom 14:7-11
Romans is one of the truely great books of the New Testament. You can find the answers to almost any question there. But....there are more.
"Who was before a blasphemer, and a persecutor, and injurious: but I obtained mercy, because I did it ignorantly in unbelief. And the grace of our Lord was exceeding abundant with faith and love which is in Christ Jesus. This is a faithful saying, and worthy of all acceptation, that CHRIST JESUS CAME INTO THE WORLD TO SAVE SINNERS; of whom I am chief." 1 Tim 1:13-15
"For this is good and acceptable in the sight of God our Saviour; WHO WILL HAVE ALL MEN TO BE SAVED, and to come unto the knowledge of the truth. For there is one God, and one mediator between God and men, the man Christ Jesus; Who gave himself a ransom for all, to be testified in due time." 1 Tim 2:3-6
"This is a faithful saying and worthy of all acceptation. For therefore we both labour and suffer reproach, because we trust in the living God, WHO IS THE SAVIOR OF ALL MEN, SPECIALLY OF THOSE WHO BELIEVE. These things command and teach." 1 Tim 4:9-11
"Meditate upon these things; give thyself wholly to them; that thy profiting may appear to all. Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee." 1 Tim 4:15-16