What does it mean to "believe" in your interpretation? Most Protestants seem to take the passive approach that belief is of the mind and heart. I would say the Church adds the physical approach such that it isn't enough to confess that you believe... you have to obey. 1 Cor 7:19 Circumcision is nothing and uncircumcision is nothing: but the observance of the commandments of God. We are called to obedience. But not the obedience of slaves and servants, the obedience of sons. We reap not the wages of laborers but the inheritance of family.
Abraham followed God from Ur and had a personal relationship with Him for decades before his flesh was marked. Even so, he was commanded to sacrifice his only son to God. He wasn't stopped by the angel at the point of agreement, he was stopped in the attempt. At this, God made His Covenant with Abraham which He fulfilled in Christ.
When we tell our children to get up and go to school it isn't enough that they look at us and "believe" and agree that that would be a good thing--they have to obey! What then are we to do in our belief? These are the works of charity and mercy and we have been given the Sacraments to strengthen us in our labors. When Christ said, "Do this in remembrance of me", we do just as He did and it is made real at the power of His Word as it was when He first accomplished it. This is what "remembrance" meant to the Jews at Passover. It wasn't just a memory they were recalling, they were reliving and making the event real in their homes and hearts. We do the same in the Eucharist and Christ is really and truly present in His Body, Blood, Soul and Divinity as He was at the Last Supper.
We obey His commands.
We believe, and the bible tells us, that faith is a gift of God, and doesn't come from us. There is where you stumble