I see what you are saying and i understand that interpreting verses from the overall context of all scripture is extremely helpful in minimizing a lot of potential misinterpretations, but since lots of scriptures are translated to the word "believe" or "believes" and they all came from a root that meant something quite immensely different than what this means to us today in our modern language, this has created a great misunderstanding among many.
When people see "all you have to do is believe" 20 times and "pick up your cross and follow me" and "abide in me as a branch to the Vine" only one time each, the tendency is to think, "all i have to do is believe". And of course they apply the watered down modern meaning of this word "believe" rather than applying the much more powerful and transformational meaning of the original root word.