I understand that many people were greatly helped by Piper's preaching, and so I do not wish to be insensitive, but as someone who had to admit recently that a minister I greatly loved betrayed our trust on the issue of the gospel itself, I am not afraid of questioning someone who greatly helped me and whom I admired.
Piper's view of justification greatly troubles me, and I have always been a little wary of his teachings, though I never thought until now that he was truly concerning. He seems to be one of the great masters of the word salad (he may have said something that helped you, and maybe he hasn't always been like this, but I have noticed that a lot of at least what I have heard of him has been either random or ambiguous and so it is rare that he actually comes out with clear-cut error, but he often is too soft on people that deserve critique and harsh on the right thing). If you haven't heard about this, I would recommend watching Rev. Patrick Hines on the issue. He seems harsh at some points, but it is because he has watched the whole thing before he shows the parts that make your heart drop. I really think he is gracious overall but critical in a godly way. TLDW: What he teaches is almost a heresy, and quite popish, and not the Puritan definition of final justification – that what we call justification and what he calls initial justification is us getting to a point wherein we can please God and He favours us, and then that final justification and what we call just ordinary justification once more is when we are actually saved – and he does appear to believe that one can be initially justified but not 'going to heaven', falling into Galatianism in the middle of his train of thought, although he understands the passage correctly. He seems to misinterpret James in a similar way to papists, and so his soteriology follows (initial justification being comparable to the 'state of grace' of Rome). Nevertheless, if anyone is quick to judge this assessment of the situation, I would highly recommend watching the video on Christian Sermons and Audio Books on YouTube.
I am also concerned (but less so, yet I think it points to a greater issue) by his rewriting of the catechism's first question, which I was not so annoyed by until some ministers kept quoting him and saying they agree with him (almost as if they were saying above the Westminster Divines' work of great godly wisdom) and the fact that he, New Calvinists, and 'Piperites' hardly understand the Standards they claim to respect. He completely misunderstands the intention of their usage of the word 'enjoy' and therefore endeavours to redefine the catechism and redirect our wills to his 'Christian hedonism' (which to me seemed OK at first but now appears abhorrent in hindsight). (This is, his 'It should be "Man's chief end is to glorify God by enjoying Him for ever"', which implies and has caused many followers to believe that happiness is more important than serving, though serving should be done in joy. We have too much will-worship these days to be perpetuating such an interpretation – and the enjoying is not necessarily the joy one gets during Christian experiences such as joyful parts of worship, thanksgiving, reward, good providence, and hearing of the gospel, but the whole experience of God, and it seems quite man-centred. As far as I am aware (who knows little in this regard, which actually concerns me more about the greatly academic Piper), unregenerate man glorifies God passively (insofar as God uses him for His glory) and enjoys the common graces of this life, and regenerate man glorifies God actively and enjoys eternal life and all the blessings and benefits which accompany or flow from justification, adoption, and sanctification, and so all are 'enjoying' Him in a purely spiritual sense and not an emotional one, therefore 'Christian hedonism' has nothing to do with this.)
We cannot afford to compromise on such issues as he has erred on to a doubt-inspiring degree, especially in this day and age wherein many ministers are exegeting correctly in many a way, but are sidestepping or confounding the core gospel, and doubly especially as Confessionally Reformed Christians.
