Grace is favour-which NONE of us deserve, yet you maintain that it is 'conditional'!..so i see it,correct me if am wrong.
There is also more than one definition of sin, for there are many 'faces' of sin, eg.,
- ‘Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.’
1 John 3:4.
- ‘All unrighteousness is sin.’ 1 John 5:17
- ‘Everything which is not of faith is sin.’ Romans 14:23…and this is where your take on the Faith concept is wrong ma Brother.

Romans 3:19-24 (New International Version)
"Now we know that whatever the law says, it says to those who are under the law, so that every mouth may be silenced and the whole world held accountable to God.Therefore no one will be declared righteous in his sight by observing the law; rather, through the law we become conscious of sin.
Righteousness Through Faith
But now a righteousness from God, apart from law, has been made known, to which the Law and the Prophets testify. This righteousness from God comes through faith in Jesus Christ to all who believe. There is no difference, for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus".

The love for, and faith in Our Heavenly Father, with the belief in our Lord Jesus Christ, is the only way to do 'good works'. That is why faith without works is dead, just like works without faith is.

Without faith, we have absolutely no understanding of what love truly is. And everything we do without that 'godly love' which comes from faith, is done for the wrong reasons and completely worthless.

Without faith, we do things to be seen, to be appreciated, or to justify ourselves to the world and to ourselves as well. These things are useless.

But with faith, we learn God's love for one another, and for His creation. And it is that 'true love' that makes 'true works'. Not that we have done a single thing... but that God has done something beautiful through us! And this is only possible in our belief in the Lord Jesus! That is why the crowns will be cast at HIS feet, and not remain on our heads.

So worthless works are our own because they are worthless. And those true 'good works', are not our own, and thus have true value. That is why they should be done in secret. That is why we are not to boast. They are not ours when done for the right reason. God gets ALL the glory.

This even goes for what we like to call our 'spiritual gifts. They are not ours! They are God's! And they are not 'ours' to have, but they are God's to give THROUGH us. So our 'spiritual gifts, are FROM God, and FOR others. We just have the privilege of being messengers, delivering God's gift to our fellow human beings. So we must not even dare brag about our 'spiritual gifts' as if they make us something special.

This is what faith is, love is, and what 'works' are. When something is done in 'true godly love', there is no law, only faith. And only God may have the glory.

Is it "Blind faith" or "Prove all things"?

Please allow me to answer you using the scriptue. But, let us first establish the ground rules.
All Bibles in existence today tell us that Christians are taught by Jesus himself:

"And Jesus answered him, The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord: And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment." Mark 12:29-30. And now who's teaching people about trinity? Is it Jesus? You know who it is.

They are also told "Prove all things; hold fast that which is good" 1 Thessalonians 5:21
And "For God is not [the author] of confusion" 1 Corinthians 14:33. Now who's telling us to forget about laws?

So, contrary to the teachings of many, Jesus did not want his followers to believe everything they were told on "blind faith."
Rather, he wanted his followers to believe "with all thy mind." He wanted us to THINK in order to protect his words from corruption.
Let us comply with the teaching of the one God has sent, Jesus, and see where the truth and our minds will lead us.

Based on all the above, is this not fair? Is this not what the Bible and Jesus himself say?
So let us use our minds and be inquisitive. Let us ask questions so that we may indeed be able to truthfully claim that we have loved God "with all our minds."