There is the concept in the Bible that since God can see into our heart our best works are as filthy rags to the purity of God. That is why he gave us grace. With grace through faith in Jesus God sees us as cleansed from sin.
I know there are differing concepts out there regarding religious doctrines. You and I just encountered one regarding Passover and Unleavened bread. You found a website many trust and posted their "Concept" of Passover being a 7 day feast. Lot's of folks believe this because of this and other websites, along with some Jewish traditions, etc.. But if we just study the Word of God apart from the influence of all these other voices, we find a different Biblical reality. That Passover, according to the Christ who created it, is actually a one day Feast followed by Feast of Unleavened Bread, which is the 7 day Feast with Sabbaths on both end.
This same scenario is repeated hundreds of times a day in this world. Other voices convincing folks of things which are not true about God's Word. This started with Eve and we are warned about this over and over.
So regarding the understanding of true faith, there are also different "concepts" out there that paint a different picture of the Bible's definition.
For instance it is widely taught that if I deny my self as the Christ commands, and follow HIS definition of "Good works" and deny what I or religious man believes is Holy, and submit myself to God's definition of "Good" and His definition Holy, I am somehow doing my own Works. And doing so is a rejection of Grace.
But the Biblical Reality is that if I submit myself to the Christ (Word which became Flesh) and follow His Word, I am no longer guiding my own footsteps, rather, the Christ is guiding my own footsteps. Therefore it is no longer me, but the Christ within me.
So then I have denied "my works", which are filthy rags, and embrace the Works of God that the Scriptures teach "He created beforehand that I should walk in them".
Throughout the Bible God directs us to "Follow Him", to keep "His Commandments" over the religious instruction (other voices) of the religions of the land, which is how He teaches we are to Love Him. Those who "do" these sayings, are loved by Him and receive His Mercy, like Abraham.
John 14:
23 Jesus answered and said unto him, If a man love me, he will keep my words:
and my Father will love him, and we will come unto him, and
make our abode with him.
He said the same thing as the Word of God which created the Commandments in the first place.
"And shewing mercy unto thousands of them that love me, and keep my commandments."
Those who choose the "other voices" and reject the instructions of God like Eve and the Pharisees He said:
Matt. 7:
23 And then will I profess unto them, I never knew you: depart from me, ye that work lawlessness.
This is why Jesus said by their "works" ye shall know them. This is why I have "come out" of the religions of the land who call Him Lord, Lord, but do not what He says.