A lot of false dichotomies are presented within false Christianity, where a pendulum swings back and forth between theology and practice in different time periods and within different ecclesiastical bodies. But the very characteristic of false religion is the emphasis of one truth or right practice to the exclusion of another truth or right practice. Paul exhorts Timothy to "pay close attention to yourself and to your teaching; persevere in these things, for as you do this you will ensure salvation both for yourself and for those who hear you" (1 Tim 4:16). In other words, both your lifestyle (i.e., character as it is represented in your practice, not just as you think of yourself, as your works will display who you really are beyond our tendencies as a spiritually blinded people to self deceive) AND in your teaching (i.e., what you believe and communicate to others that they should believe). Salvation is in watching both carefully, not in just watching one. Let me illustrate and end with this story.
A father was taking his young son fishing by an old WWII ship graveyard. The boy asked his father, "Dad, I'm not sure what is more important to God, whether to believe what is true, or to do what is right. If I were to fail at one of these, which one can more easily be dismissed from my life than the other?
The Father thought for a moment, and then steered the boat closer to two big naval ships that had been sunk by torpedoes. He moved the boat past the first and told his son to observe the bow as it stuck up from the deep, displaying that it had been sunk by a torpedo blowing a hole in the stern. Then he passed by the other and told his son to observe how the stern stood out of the water, displaying that it had been sunk by a torpedo blowing a hole in the bow.
Then, as he moved the boat further from the two sunken ships so that his son could see them both well together, he said, "Which side of these two ships, which have become the gravestones of these unfortunate sailors, was lost without complete devastation to the whole ship?"
The son answered, "Neither."
The father, in answer to his son's question, then said with a confirming nod and sober whisper, "Neither."