The great learning and genius of Milton, have scarcely raised him more admirers, than the part he acted upon the political stage, has procured him enemies.  He was in his inclination a thorough Republican, and in this he thought like a Greek or Roman, as he was very conversant with their writings.  And one day Sir Robert Howard, who was a friend of Milton’s, and a well wisher to the liberty of his country, asked him, how he came to side with the Republicans?  Milton answered, among other things, ’Because theirs was the most frugal government; for the trappings of a Monarchy might set up an ordinary Commonwealth.’  But then his attachment to Cromwell must be condemned, as being neither consistent with his republican principles, nor with his love of liberty.  It may be reasonably presumed, that he was far from entirely approving of Cromwell’s proceeding; but considered him as the only person who could rescue the nation from the tyranny of the Presbyterians, who he saw, were about to erect a worse dominion of their own upon the ruins of prelatical episcopacy; for if experience may be allowed to teach us, the Presbyterian government carries in it more of ecclesiastical authority, and approaches more to the thunder of the Vatican, than any other government under the sun.  Milton was an enemy to spiritual slavery, he thought the chains thrown upon the mind were the least tolerable; and in order to shake the pillars of mental usurpation, he closed with Cromwell and the independants, as he expected under them greater liberty of conscience.  In matters of religion too, Milton has likewise given great offence, but infidels have no reason to glory.  No such man was ever amongst them.  He was persuaded of the truth of the christian religion; he studied and admired the holy scriptures, and in all his writings he plainly discovers a religious turn of mind.

When he wrote the Doctrine and Discipline of Divorce, he appears to have been a Calvinist; but afterwards he entertained a more favourable opinion of Arminius.  Some have thought that he was an Arian, but there are more express passages in his works to overthrow this opinion, than any there are to confirm it.  For in the conclusion of his Treatise on Reformation, he thus solemnly invokes the Trinity: 

’Thou therefore that sittest in light and glory unapproachable, parent of angels and of men! next thee I implore omnipotent king, redeemer of that lost remnant, whose nature thou didst assume, ineffable and everlasting love! and thee the third subsistence of the divine infinitude, illuminating spirit, the joy and solace of created things! one tri-personal god-head.’

In the latter part of his life he was not a professed member of any particular sect of christians; he frequented no public worship, nor used any religious rite in his family; he was an enemy to all kinds of forms, and thought that all christians had in some things corrupted the simplicity and purity of the gospel.  He believed that inward religion was the best, and that public communion had more of shew in it, than any tendency to promote genuine piety and unaffected goodness.