Yes the Bible is relevant for today. God never changes but how He deals with men does. Today we are living in the age of grace where God is dealing with everybody alike through what the Lord Jesus Christ did on the cross for all that would believe and trust in Him. The problem with people today, they don't study or believe God's Word. Think about this, If people would have believe God's Word they would have know that the world was not flat but instead it took them a long time to know that. Isaiah 40: 22 It is he that sitteth upon the circle of the earth, and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in: Also, if you read the Book of I Corinthians, you will find that people act the same way today. They are babes just like they were then. 1 Corinthians 3: 1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.