I am not a priest, but I can quote a priest, Father Garrigou Lagrange, from his book, "Our Savior and His Love for Us."
"The Mass is a sacramental sacrifice substantially perpetuating in an unbloody manner the sacrifice of the Cross..."
"As the Council of Trent explains, the Sacrifice of the Mass is in substance the same as that of the Cross, because it is the same victim, really present on our alters, that is offered up and because it is offered up by te same principal priest."
"The Mass is therefore a real sacrifice, but an unbloody one. It is not merely a symbolic sacrifice or the simple re-enactment of a past sacrifice, for the victim is really present and not merely the image of this victim. There is also the real oblation of the victim and not merely a symbol of this oblation. But in this ubloody sacrifice, the real and bloody immolation of Calvary is merely symbolized and commemorated, and its fruits are applied to us. As the theologians say: the Mass is a true, unbloody sacrifice which represents the bloody immolation of the sacrifice of the Cross."
"After His resurrection and ascension, or Savior, who is a priest forever, did not cease to exercise the principal act of His priesthood, and He does this especially through the Holy Sacrifice of the Mass."
"It is certain that the glorious Christ does not cease to love us, to adore His Father and give thanks and offer Himself up to Him. This interior act of oblation, ever alive in His heart, is the soul of the Sacrifice of the Mass."
The bold lettering is mine. I just wanted to emphasize those points. The main point is that the Sacrifice of the Mass is IN SUBSTANCE the same as that on Calvary. This latter quote by this priest was the best clarification, I thought. Alot of this is still a great mystery to me, but these words from this priest clarified alot for me, that's why I wanted to share it with you and whoever else...
One thing I will say-The truth that is presented to me in scripture and by the holy spirit is this-God, Jesus, and the spirit are separate, but one (duh). Everything is in, with, and through Jesus. In John 1:1, it states that the word was with God in the beginning, the same "in the beginning" that is the beginning of the bible in Genisis. So, he, and his Father, are from forever to forever. Alpha and Omega. They have no beginning and no end. They are.
Now, strangely enough, men are trying to define Jesus and God now. They are attempting to scientifically explain him and discover him. Much like the tower of Babel. They got together and built the tower of Babel to reach up to heaven, and God put an end to it. Now, men are at it again, this time with a particle accelerator. They have gathered the nations, and together built the CERN complex. 500 billion is what I believe they collectively spent. They are trying to discover "the God particle". They are trying to explain why everything is held together. They know many mind blowing properties and laws of Physics, and much , much more, but what they cannot explain is the basic fact that something must bind things together. Why does a nucleus have positive and negative charges and not come apart? They postulize a "God particle" that must be the force that accomplishes this. That, to me, is Jesus. Jesus is everything. He is the force in the universe, everything is created and exist through him. He is you, me, everything you see, touch,hear, feel, and the things that you can't percieve or comprehend. He is good and holy, but Satan infected this perfection with evil, and he will be destroyed, and we will once again be holy and undefiled. To me, that is what he ment "this is my body, this is my blood". He was actually stating that he is everything, which is true. The water there was unfit to drink, and if there wasn't any rain there wasn't any wheat or wine, and you starved to death and died physically. Without him, you die spiritually, he is everything. His sacrifice was a lethal one time mortal blow to satan, and he reconciled us who believe in him. We who believe and love him do what he commands, and that is to love each other, Catholic or not, and obey the commandments. After he comes, we will find everything out from him, and we will fully understand, and I am living for that moment...... Peace