If you can remember tattva gyan (philosophy) at all times, you are unlikely to comment sin. Even if your mind does wander towards the world or bad thoughts, you will immediately remember that Shyamsundar is sitting inside of you, noting your every thought. You even tend to hide things from your Guru and therefore commit sins by maintaining your privacy. However, this privacy is ruining you because it is a big stumbling block on the path of devotion. You fail to believe that God is omnipresent. If you believe it, you will realize God.
Thus, tattva gyan is extremely important. There are several topics related to tattva gyan i.e. What is raag-dvesh or panchmahabhut or abhinivesh and so on? However,you need only remember three points : sambandh, abhideya and prayojan. What is our relationship with Shree Krishna? What should we do to establish and complete that relationship, and what is the aim behind what we are doing? As your tattva gyan deepens, you will keep moving closer to God.