Therefore the Son of man is Lord also of the sabbath. Mark 2:28.
Scripture is TRUTH because it is God breathed and God is truth and is that by which everything else is compared. There is no greater authority than God and God speaks to us through Scripture, His Word.
His word is powerful because it is truth and truth will demolish lies every time. That's why the first thing Satan did when he tempted Eve was question the word of God given to them with *Did God REALLY say....*?
Matthew 22:29 But Jesus answered them, “You are wrong, because you know neither the Scriptures nor the power of God.
Matthew 5:17-20 17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. 19 Therefore whoever relaxes one of the least of these commandments and teaches others to do the same will be called least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven. 20 For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.
Psalm 119:89 Forever, O Lord, your word is firmly fixed in the heavens.
Ephesians 6:16-18 16 In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; 17 and take the helmet of salvation, and the sword of the Spirit, which is the word of God, 18 praying at all times in the Spirit, with all prayer and supplication. To that end keep alert with all perseverance, making supplication for all the saints,
Hebrews 4:12 For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart.
2 Timothy 3:14-17 14 But as for you, continue in what you have learned and have firmly believed, knowing from whom you learned it 15 and how from childhood you have been acquainted with the sacred writings, which are able to make you wise for salvation through faith in Christ Jesus. 16 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17 that the man of God may be complete, equipped for every good work.
Romans 15:4 For whatever was written in former days was written for our instruction, that through endurance and through the encouragement of the Scriptures we might have hope.