We know this from 2 Timothy 3:16-17, “All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work.”
Tunajua hili kutoka 2 Timotheo 3:16-17, "Kila andiko, lenye pumzi ya Mungu lafaa kwa mafundisho, na kwa kuwaonya watu makosa yao, na kwa kuwaongoza, na kwa kuwaadibisha katika haki; ili mtu wa Mungu awe kamili, amekamilishwa apate kutenda kila tendo jema."