# For
This verse is the beginning of an interruption of Paul's main argument, in which he gives the reader extra information. If you have a way to mark an interruption like this in your language, you can use it here.
# a law to themselves ... do not have the law
"have God's laws already inside them ... actually do not have the law"
# they do not have the law
"they do not actually have the laws that God gave to Moses"