"However, the Most High does not dwell in houses made by human hands; as the prophet says: ‘Heaven is My throne, and earth is the footstool of My feet; what kind of house will you build for Me?’ says the Lord, ‘Or what place is there for My repose?" (Acts 7:48-49)
"The God who made the world and all things in it, since He is Lord of heaven and earth, does not dwell in temples made with hands; nor is He served by human hands, as though He needed anything, since He Himself gives to all people life and breath and all things." (Acts 17:24-25)
If God does not dwell in places such as tabernacles or synagogues (where animal sacrifices are performed), then the Eucharist is just an ordinary peace of bread and priests do not have the power to transubstantiate the communion elements.
We are also told in the New Testament that we need not think of God as being a material object:
"Being then the children of God, we ought not to think that the Divine Nature is like gold or silver or stone, an image formed by the art and thought of man." (Acts 17:29)
Is not the Eucharist wafer manna, which is material? The bread and wine used in the Mass can at most be considered an image of Jesus Christ. God the Son ascended into heaven above:
"For Christ did not enter a holy place made with hands, a mere copy of the true one, but into heaven itself, now to appear in the presence of God for us." (Hebrews 9:24)
We have been commanded by Jesus Himself to not believe people when they claim that He is present in various locations:
"Then if anyone says to you, ‘Behold, here is the Christ,’ or ‘There He is,’ do not believe him. For false Christs and false prophets will arise and will show great signs and wonders, so as to mislead, if possible, even the elect. Behold, I have told you in advance. So if they say to you, ‘Behold, He is in the wilderness,’ do not go out, or, ‘Behold, He is in the inner rooms,’ do not believe them." (Matthew 24:23-26)
The above exhortation would most certainly be applicable to Roman Catholic priests, since they claim that Christ is brought into the presence of the attendees through the consecration of the bread and wine. This is sufficient proof that transubstantiation is a false doctrine.