What are the objections to Newton's critique of 1 John 5:7 and 1 Timothy 3:16?

In "An Historical Account of Two Notable Corruptions of Scripture", Isaac Newton argued that 1 John 5:7 was a corruption of the early church and did not appear in the original Greek scriptures. He makes a similar claim regarding 1 Timothy 3:16. 1 John 5:7 is the strongest biblical reference to the trinity. Is there an objection to Newton's historical analysis of these verses? > 1 John 5:7 -- For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. > > 1 Timothy 3:16 -- And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.