There are many texts in the book of Revelation that soundly refute
Modalism. Two such examples are:
The Revelation of
Jesus Christ, which God gave unto him, to shew unto his servants things which
must shortly come to pass; and he sent and signified it by his angel unto his
servant John. (Rev 1:1)
He that overcometh,
the same shall be clothed in white raiment, and I [Christ] will not blot out
his name out of the book of life, but I will confess his name before my Father,
and before his angels. (Rev 3:5)
In both these texts, Jesus is presented as being as numerically distinct
from the Father as the Father is numerically distinct from John the Revelator
and God's angels. What is also interesting is that, in Rev 1:1, Jesus gives the "Revelation" (Greek: αποκαλυψις) to John just as the Father gave it to Jesus. One must engage in all sorts of mental gymnastics if one wishes to preserve belief in Modalism!
While those who hold to a form of Modalism will agree that
John and the angels are numerically distinct from the Father, they are
inconsistent (and guilty of eisegesis, too!) when approaching these texts, as
they cannot allow for the Son to be numerically distinct from the Father,
notwithstanding the clear meaning of these and other texts (e.g., Rev 5:5-6, where Jesus [the Lamb] is in a different location than the Father, again, showing them to be numerically distinct from one another).