Yes, Christians are allowed to break national laws and become criminals, if national laws go against the laws of the Holy Bible.
It was right and just for Kim Davis not to issue marriage license for gay marriage.
In fact, issuing gay marriage licenses will make you guilty before God, and you may be sent to eternal damnation in Hell for it by Jesus the Judge on the Judgment Day.
God’s Law is absolute, and God will enforce God’s Law and punish anyone who go against the anti-gay laws of the Holy Bible. Romans 1 is very clear on this point.
In fact, Christians must break local, state, and federal laws that go against the Law of God.
This is expected of Christians. Apostles of Jesus Christ broke religious tolerance and “hate laws” of the Roman democracy and were arrested for it.
Christians must submit to the authority of the Holy Bible against any earthly laws or orders (in the miitary, in the police force, in the Pentagon, and in the context of intelligence/special forces operations).