Many things are not predestinated by God. Murders, rapes, thefts and many other things are not predestinated by God.
In context, the verse you cited does not say that
all those who will be rejected but will claim to have prophesied, cast out devils and did miracles in Jesus' name were never at any time known by God.
Mat 7:22
Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works?
Mat 7:23
And then will I profess unto
them, I never knew you: depart from me, ye that work iniquity.
There may also be many who say to Him in that day, "Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works," whom He did know bu still rejects. And many "who say to Him in that day, "Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works?" whom He accepts. Jesus mentioning only one category, does not mean that is the only possible category.
And in context, the other verse you cited does not say
everything is predestinated, only that
certain people, those whom He already had known before they believed, were predestinated
to a particular end, namely,
conformity to the image of God's Son.
Romans 8:29
For whom he foreknew, he also predestinated to be made conformable to the image of his Son; that he might be the firstborn amongst many brethren.
Attributing
one characteristic to
one category of people
(those whom He foreknew before they believed) does not exclude
other categories of people
(those whom He foreknew who never believe) from having
the same characteristic.
There is nothing in scripture that indicates to me that
everything,
including all sins, are predestinated by God.