That being said, the concept of Mediatrix of all graces is not a denial that God dispenses graces through other means. To do so would be an error. Rather, it is an affirmation that through her intercession, her prayer at the throne of her Son, Jesus Christ, she can obtain all things. God is the one who does the "heavy lifting." Then again, since your heretical theology denies the intercession of the saints, you will not be convinced by this.
Where is the Scriptural evidence that Mary intercedes for anyone?
Heresy is defined as something contradicted by Scripture and expressly forbidden by God.
Labeling Mary as "co-redemtrix" and "co-dispenser of grace" are heresies men will be called upon to defend before Jesus Christ.
And they will fail.
So Mary is the Mediatrix of ALL graces but God can dispense graces through other means?
Your definition of "all" is quite interesting.
Jacques-Benigne Bossuet wrote this....
“Mary stands near the Cross. With what eyes she contemplates her Son all covered with blood, all covered with wounds, in form now hardly a man! The sight is enough to cause her death. If she draws near to that altar, it is to be immolated there: and there, in fact, does she feel Simeon’s sword pierce her heart.
“But did her dolors overcome her, did her grief cast her to the ground? Stabatjuxta crucem: she stood by the Cross. The sword pierced her heart but did not take away her strength of soul: her constancy equals her affliction, and her face is the face of one no less resigned than afflicted.
“What remains then but that Jesus who sees her feel His sufferings and imitate His resignation should have given her a share in His fruitfulness. It is with that thought that He gave her John to be her son: Woman, behold thy son. Woman, who suffer with me, be fruitful with me, be the mother of my children whom I give you unreservedly in the person of this disciple; I give them life by my sufferings, and sharing in the bitterness that is mine your affliction will make you fruitful.”
Mary’s love for Jesus was enough to make her a martyr: “One Cross was enough for the well-beloved Son and the mother.” She is nailed to the Cross by her love for Him. Without a special grace she would have died of her agony.
Mary gave birth to Jesus without pain: but she brings the faithful forth in the most cruel suffering. “At what price she has bought them! They have cost her her only Son. She can be mother of Christians only by giving her Son to death. O agonizing fruitfulness! It was the will of the Eternal Father that the adoptive sons should be born by the death of the True Son. What man would adopt at this price and give his son for the sake of strangers? But that is what the Eternal Father did. We have Jesus’ word for it: God so loved the world as to give His only begotten Son (John 3:16).
“(Mary) is the Eve of the New Testament and the mother of all the faithful; but that is to be at the price of her Firstborn. United to the Eternal Father she must offer His Son and hers to death. It is for that purpose that providence has brought her to the foot of the Cross. She is there to immolate her Son that men may have life. She becomes mother of Christians at the cost of an immeasurable grief. ” We should never forget what we have cost Mary. The thought will lead to true contrition for our sins. The regeneration of our souls has cost Jesus and Mary more than we can ever think.
For me, just thinking about Mary there at the foot of the cross and what she endured... it is enough for me to cry like a baby.
I can only pray that our Blessed Lord forgives some of our separated protestant brothers and sisters for what they do and say about Our Blessed Mother
I wish you a Blessed day!
SINCE SCRIPTURE DENIES ANY SUCH USURPING INTERCESSION OF THE SAINTS, we will continue to deny any agency of Mary in such a regard.