By thinking we do need to do something more than faith in what Christ provided on the Cross, we fail to believe in what He provided at the Cross.
It only takes a smidgen more faith that no faith whatsoever for saving faith.
Your comment: “By thinking we do need to do something more than faith in what Christ provided on the Cross, we fail to believe in what He provided at the Cross.”
That is not true. God gave us free will to either accept Him and follow Him or reject Him and follow the ways of the world and Satan.
Many have been sold on faith alone. This is heresy and not God’s Truth.
What is faith? The pharisees had faith and preached their faith, but they didn’t practice their faith. Mat 23:2
Christ’s suffering and death redeemed mankind. We accept His gift by Baptism and keeping His commandments (returning His love).
So you feel that one only need a “smidgen more faith” to accept God’s salvation?
Mortal Sin is a willful turning away from God that destroys the grace and relationship with God. Baptism forgives our sins at the time of Baptism. We need to repent for subsequent sins and do penance with sincere contrition and not die in mortal sin.
Faith is accepting God’s Truth and keeping His Commandments. This includes eating and drinking God’s Body and Blood. John 6:53-54