The psalmist knew the value of truth when he wrote in Psalms 119:72, "The law of thy mouth is better unto me than thousands of gold and silver." He writes in Psalms 119:127, "Therefore I love thy commandments above gold; yea, above fine gold." He advises, as the personification of wisdom, "Receive my instruction, and not silver; and knowledge rather than choice gold" (Prov 8:10).
What is truth? Jesus provides the answer in His prayer on the night of His betrayal and trial. He prays for His disciples in John 17:17, "Sanctify them through thy truth: thy word is truth."
Solomon writes in Proverbs 4:5, "Get wisdom, get understanding: forget it not; neither decline from the words of my mouth." He writes in Proverbs 4:7, "Wisdom is the principal thing; therefore get wisdom: and with all thy getting get understanding." What he says in the middle verse (Prov 4:6) is important:
"Forsake her not, and she shall preserve thee: love her, and she shall keep thee."
It does not matter how much you know. Without wisdom, all the knowledge in the world will do you no good. When Epaphras informed Paul of the Colossian brethren's love in the Spirit (Col 1:7-8), he wrote in Colossians Colossians 1:9:
For this cause we also, since the day we heard it, do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding.
Notice that he said that he prayed that they would be filled with knowledge and wisdom and spiritual understanding.
Solomon writes in Proverbs 4:13, "Take fast hold of instruction; let her not go: keep her; for she is thy life." Solomon believed instruction should be high on one's list of priorities! He wrote just six verses earlier (Prov. 4:6), "Wisdom is the principal thing..." Now he puts instruction at the top of the list along with wisdom. He will write later, "Receive my instruction, and not silver; and knowledge rather than choice gold" (Prov 8:10). He will write in Proverb 13:18, "Poverty and shame shall be to him that refuseth instruction: but he that regardeth reproof shall be honoured." He will put it in even stronger terms in Proverbs 15:32:
"He that refuseth instruction despiseth his own soul: but he that heareth reproof getteth understanding."
Many have committed serious sins because of a lack of instruction in the Word of God. In doing so, they have seriously harmed themselves and/or other.
Where do you get instruction? Paul answers in 2 Timothy 3:16-17
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.