James had been educated in Scotland by Presbyterian ministers and consequently felt there were grounds for cautious optimism that the new king would be sympathetic to the reforms they desired. They therefore presented him with the millenary position as he traveled to London for his coronation 1603. The petition was moderate in tone; it demanded the removal of papist practices, more emphasis on preaching in church services, better educated clergy and the ending of pluralism and non-residence, whereby a minister could hold more than one church living and appoint curates to take services in his absence. In 1604 James held the Hampton Court Conference in response to this. During the conference he made it clear that he would not countenance Presbyterian reform although he was prepared to improve the value of church livings and to reduce, pluralism and non-residence. However, little was done to honor these promises. The only possible achievement of the conference was a decision to commission a new English translation of the bible, which resulted in the publication of the Authorized Version in 1611. In the conference, James showed himself to be nearly as hostile as Richard Bancroft to puritan aspirations. Fortunately for the puritans, many bishops were more tolerant and sympathetic than James and Bancroft.
In 1604, Convocation passed canons (church regulations) that specifically enforced and defended the very practices puritans disliked (such as bowing the head at the name of Jesus and the use of the sign of the cross in baptism). These articles were a serious blow to many Puritans because they could no longer try to ignore practices of which they disapproved. About 90 puritans who would not conform were deprived of their livings. A much larger number remained within the church, protected by a friendly bishop or merely accepting the inevitable. Puritans complained about this, particularly to Parliament whose consent to canons many thought necessary, but was not obtained.
England's Roman Catholics hoped that James would treat them better than Elizabeth had done, since they had supported his mother, Mary Queen of Scots and his wife, Anne of Denmark, had converted to Catholicism.
At first James treated the Catholics with caution by continuing with Elizabeth's policy of fining Roman Catholics for recusancy, but reducing the fine. However in 1604 this leniency stopped and James ordered all priests and Jesuits out of the country and recusancy fines were put up to the original level. Catholics were further disappointed when James made peace with Spain which destroyed Catholic hopes of liberation by a Spanish invasion.
A few Catholic gentlemen turned in desperation to violence. The was a plan to blow up the Houses of Parliament when King, Lord and Commons were all present and then seize control of England.
James soon faced Roman Catholic conspiracy. Robert Catesby, Thomas Percy and Guy Fawkes led some Catholic gentleman in the Gunpowder Plot to blow up the king and his two sons on the day that parliament opened. After this they had intended to capture James’ daughter, Princess Elizabeth and rule through her.
One of the conspirators warned his relative, Lord Monteagle not to attend the opening of Parliament. Lord Monteagle took the letter to the government and the whole plot unraveled. On 5 November 1605, Guy Fawkes was arrested amongst his barrels of gunpowder in the cellar beneath the Houses of Parliament. Under torture, he confessed and gave the names of his fellow conspirators. The conspirators fled but were pursued and those who were not killed were captured and executed.
The involvement of the Jesuit priest, Henry Garnet, who confessed to knowing of the plat in advance, increased anti-Catholic feeling in England and by James himself who thought it, was necessary to enforce more strict laws.
In the aftermath of the plot, Parliament passed new legislation against English Catholics; Catholics were forbidden to live in or near London or to hold public office. Also Recusancy fines were increased and Catholics were required to take a new oath of allegiance which denied the Pope’s authority to depose the king. Catholics were happy to demonstrate their political loyalty by taking it. So in conclusion after the Gunpowder plot which was realistically only supported by a few Catholics, the Catholics were no more trouble to James.
In conclusion, I feel both the Puritans and the Roman Catholics were of equal threat to James between 1603 and 1606 although the Catholics were more of a threat to James safety because of the Gunpowder Plot of 1605. Although it must be remembered only a few extreme Catholics were part of this, so it was of not as much of a threat as one may think. By 1606 I feel James had dealt with them well, using measures that were fair and not more extreme than necessary.