Galatians 3:10, For as many as are of the works of the law are under the curse: For it is written, Cursed is every one that continueth not in all things that are written in the book of the law to do them.
My exposition: As many as are the works of the law = all those who have not put their trust in Christ and received His forgiveness through the blood of His Cross. All such people are only seeking to enter in through the only other way possible: through their own righteousness/works/law-keeping.
All these are under the curse, and are cursed because they do not keep every letter, they do not continue in every thing that is written in the book of the law to do every thing that is written in the book of the law; and the scripture proclaims a curse on every one who does not continue in every letter of the law, keeping it perfectly from the moment they are conceived to the day they die and beyond into eternity.
If anyone puts their trust in Christ, this is not true of them, for they are not of the works of the law. Therefore they are forgiven of their imperfections and failure to keep the law perfectly all their lives.
James 2:10, For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.
My exposition: If I were to do an exemplary job of keeping the law perfectly all of my life, but in the last moment of my life I forgot to wear titzit on my hospital gown, I am guilty of breaking the whole law of God.
Matthew 5:48, Be ye therefore perfect, as your Father which is in heaven is perfect.
My exposition: God requires perfection if you are going to enter in on the basis of your own righteousness/works/law-keeping.