It was written to CHRISTIANS, including those who were Jewish converts.
And irresistible grace and God determining who must be saved and who will not be allowed to be saved is NOT a part of the teaching of Romans, which is most emphatically about our need to respond to God with FAITH.
A major them is that those who believe - whoever believes - will be saved. Not that God requires some to be saved and others to be damned, but whoever believes will be saved.
“For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. 17For in it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.”
Blessed are you, Peter. For this was not given to you by man, but by my Father in Heaven”
Remember that?
“You did not choose me. I chose you”
Remember that?
“those He predestined he also called... etc”
that too...
Maybe you should ask yourself what is so unattractive about a sovereign God.