Where does the bible say that?
Romans 3:4
4 God forbid:
yea, let God be true, but every man a liar; as it is written, That thou mightest be justified in thy sayings, and mightest overcome when thou art judged.
So the Bible says trust fully only what God has said. His word rules over all others.
2 Peter 1:20-21
20 Knowing this first, that
no prophecy of the scripture is of any private interpretation. 21 For the prophecy came not in old time by the will of man: but holy men of God spake
as they were moved by the Holy Ghost.
God moved men to speak His word. Those words are true. They are also not open to interpretation. So how do you get the right one?
Proverbs 2:1-6
My son,
if thou wilt receive my words, and hide my commandments with thee; 2
So that thou incline thine ear unto wisdom, and apply thine heart to understanding; 3 Yea, if thou criest after knowledge, and liftest up thy voice for understanding; 4 If thou seekest her as silver, and searchest for her as for hid treasures; 5
Then shalt thou understand the fear of the Lord, and find the knowledge of God. 6 For the Lord giveth wisdom:
out of his mouth cometh knowledge and understanding.
All of the words of God are true. Not one thing He says is a lie. We get the right interpretation through reading His whole word. If one scripture says thou shalt not (and no other scripture gives conditions where you shall) then the correct interpretation is thou shalt not.
If the scripture says thou shalt not and then another one some place says thou shall do this or that then we should look deeper into the words and see why it is ok in one place and not another. Gods word will explain itself if we care enough to cry out for it and look for the answers like hidden treasure.