I recommend you read Jesus' parable of the talents in Matthew 25:14-30.
Stewardship is a common theme throughout the Bible. A steward is an employee--in Jesus' day a servant, or even a bond-servant--who is responsible to his employer (or master) for whatever his master has entrusted to him.
A talent in Jesus' day was a large sum of money. In the parable in Matthew 25, the master gives money to each of three servants. To one he gives five talents, to another, two, and to the third, one. The master's expectation is that when he returns from his journey, each steward will have earned a return (loosely, a "profit") on the money entrusted to him.
Think of God's word as something God, our heavenly Master and Lord, gives to every believer for their benefit and His glory. God's expectation is that we will study his word diligently so that he will be pleased with our efforts when he greets us in the heavenly kingdom. If we have indeed studied his word assiduously, systematically, and responsibly and have incorporated its precepts into our lives, we can look forward to his saying,
"'Well done, good and faithful slave. You were faithful with a few things, I will put you in charge of many things; enter into the joy of your master'" (v.23).
By the way, the phrase "rightly dividing" means that in our approach to the Bible we need to know not only what the Bible says, but how a given passage fits into the Bible as a whole. In other words, there is a logical flow and progression within the Bible, with certain themes appearing and reappearing again and again. God expects us to take these things into account when we read, interpret, and apply his word to our lives. If your spiritual gift is in preaching or teaching or exhorting (or really any gift), a thorough understanding of the Bible is invaluable, for yourself and others.
God is not honored, I believe, when his children handle his word haphazardly. We may not start out as "master craftsmen" or "craftswomen," but over time God expects us, through diligent and systematic study, to master his word, the way a master craftsman masters his tools in making something of which he and a customer can be proud.
Opening up your Bible at random and pointing to a verse at the beginning of each day as your "thought for the day" does not constitute "studying to show [yourself] approved by God." While we cannot all be Bible scholars and theologians, we can--and God expects us to--earn his "Well done" if we nurture a love affair with the Holy Bible. After all, God's primary way of communicating his will to us is through his word, and we need to take his words seriously.