They are often written in stone; you don’t even have to think for yourself: Methodists, Presbyterians, Church of Christ, Catholics. The “laws” are doctrines decided by leaders who may or may not really believe like you will when you finally read the Bible every day and think it through.
Sure, there are gifted teachers of Scripture, but those same Scriptures challenge us to test those teachers. The Christians in Berea “. . . were more noble than those in Thessalonica . . . they received the word with all readiness of mind, and searched the Scriptures daily, whether those things were so.” (Acts 17:11) (Emphasis added)
How can you know what to believe and live by? Read the Bible every day like it is food, soul food! Then believe it. Sooner or later you will have a relationship with God that is based on the Bible.
Rather than trying to live up to a set of rules made up by a man, which rules are often in place to control you, live by what you read in the Bible. Maybe reading two or three versions, (I like the King James Version and Strong’s Concordance because I grew up hearing it). Read translations first, then maybe an interpretation, something like “The Message”. Strong’s Concordance makes the unusual words simple, and even expands on them. It’s fun to discover!!
Are you Methodist or Presbyterian? Are you Complementarian or Egalitarian? None of these philosophies are absolute truth. But the Bible is!