Truth is not a figment of the imagine of someone's imagination, it is a literal 'thing' that is both knowable and doable. Grace allows you to believe a lie as IF it is the truth, without accountablility. With God's truth, that He gave to His Son, who gave it to His own eyewitness disciples, that wrote it down, there is no such grace mentioned anywhere in those words. The Truth comes only from the Words that jesus spoke, both in the New Testament, and in the Old Testament.