2 Timothy 3:14-17
If Scripture were insufficient then it couldn't make the man of God complete, nor equipped for EVERY good work.
Scripture is certainly profitable and useful (from the Greek ophelimos) for teaching, but that doesn't make it mandatory or sufficient for teaching every individual point of theology, and not at all without Tradition (2 Thess 2:15). There are far too many seriously misguided and contradictory Christian sects in history and even today to believe that Scripture alone is sufficient.
Also, many of the Epistles weren't yet written and none of the New Testament books were in the Canon of Sacred Books when St. Paul wrote this. Much less when Timothy would have been a child. To take these verses as a justification for Sola Scriptura would mean that only the Old Testament was binding and that the New Testament wasn't necessary at all.
You are exactly right, for Jesus told this story...
19 “There was a certain rich man who was clothed in purple and fine linen and [h]fared sumptuously every day. 20 But there was a certain beggar named Lazarus, full of sores, who was laid at his gate, 21 desiring to be fed with [i]the crumbs which fell from the rich man’s table. Moreover the dogs came and licked his sores. 22 So it was that the beggar died, and was carried by the angels to Abraham’s bosom. The rich man also died and was buried. 23 And being in torments in Hades, he lifted up his eyes and saw Abraham afar off, and Lazarus in his bosom.
24 “Then he cried and said, ‘Father Abraham, have mercy on me, and send Lazarus that he may dip the tip of his finger in water and cool my tongue; for I am tormented in this flame.’ 25 But Abraham said, ‘Son, remember that in your lifetime you received your good things, and likewise Lazarus evil things; but now he is comforted and you are tormented. 26 And besides all this, between us and you there is a great gulf fixed, so that those who want to pass from here to you cannot, nor can those from there pass to us.’
27 “Then he said, ‘I beg you therefore, father, that you would send him to my father’s house, 28 for I have five brothers, that he may testify to them, lest they also come to this place of torment.’ 29 Abraham said to him, ‘They have Moses and the prophets; let them hear them.’ 30 And he said, ‘No, father Abraham; but if one goes to them from the dead, they will repent.’ 31 But he said to him, ‘If they do not hear Moses and the prophets, neither will they be persuaded though one rise from the dead.’ ”
Luke Chapter 16:19-31