The primary duty of man is to love the Lord with all our heart, soul and might. It goes without saying that we cannot love Him if we don’t know Him, just as we simply cannot know Him without studying His Word. To that end, a correct view of God is paramount if we are to worship Him correctly.
As we mature in our faith, there are many subtle nuances that must be continually revised and honed, while we continue to grow in the grace and knowledge of our Lord and Savior Jesus Christ. We see this on vivid display in our work in Africa. These people have limited language skills, and have a terribly difficult time expressing complex concepts. It’s not that they’re incapable of grasping the concepts, it’s that their limited language fails them and the concepts are incredibly difficult to communicate. Many of their questions about God or the duty of man require careful discussion (a simple example is the difference between ‘murder’ and ‘kill’, and why one is wrong and the other can – in certain situations – be the right thing to do). In similar fashion, their limited language prevents them from improving their understanding of God (eg, they had an awfully hard time grasping that God is a spirit and a spirit is a Person, but not a flesh/blood human). So when they worship God, their worship of Him is as imprecise as their understanding of Him.
The same is true for people in more advanced civilizations, of course.
If we get a basic child’s Sunday School understanding of who God is, and we don’t continue to shape and refine it as we continue to study His Word, we will continue to worship Him in ways that are less-than-correct. While it may be acceptable for a child to get a few things imprecise here and there, it is not at all appropriate for an adult to make the same misstep. When dealing with people who have become slack in their zeal for more deeper doctrine, Hebrews and Jude take on a tone of reprimand to their audiences. This should tell us that it’s not a trivial matter.
If we don’t pursue doctrine, yes, we run the risk of embracing false doctrine. But I think this is a secondary issue. The more important point, I believe, is that we stagnate in our ability to love and worship God more accurately and passionately.
Since God’s #1 aim is to bring glory to Himself through the worship of His people, we have an obligation to grow in our understanding of Him so that we can more accurately do that which we were created to do: worship Him. I think this is the primary goal of “growing in the grace and knowledge of our Lord and Savior Jesus Christ”.
I really enjoy seeing an emphasis and accountability placed on correct biblical doctrine. Our doctrine defines the God (or unfortunately the “god” in many cases) we worship, as well as the associated beliefs and practices for worshipping our God or “god”. I went for a long period in my life where I didn’t understand the difference between sound biblical doctrine and the traditions of men. On the flip side, I found it very reassuring to know that I wasn’t saved by my knowledge (or lack thereof) of the bible. I now realize that I was saved by an act of grace. All of the transaction was an act of God and to his glory. My faith (i.e. trust, the ability to believe), Jesus shed blood on the cross, and God the father’s grace were all of God, to his glory, and not the result of any contribution I thought I had made.
The real risk is as you clearly said – embracing a false doctrine. If a person doesn’t study the bible, they won’t know. There are many, many shallow folks out there (by choice – I used to be one) who let their pulpit leaders pull them down a path that can lead to a very ugly ending due to heretical, non-biblical teachings. The “god” they worship may not be the God of the bible, but a “build a bear” god (what happy parts would you like to choose to create the “god” that you’ll love?) that makes them feel warm and fuzzy in spite of their lack of repentance and obedience to the real and only God as defined by the bible…not what we like about the bible…or what may not be in the bible at all.