All doubts, however skeptical and cynical they may seem, are really a set of alternative beliefs. You cannot doubt Belief A except from a position of faith in Belief B. For example, if you doubt Christianity because “There can’t be just one true religion,” you must recognize that this statement is itself an act of faith. No one can prove it empirically, and it is not a universal truth that everyone accepts…The reason you doubt Christianity’s Belief A is because you hold unprovable Belief B. Every doubt, therefore is based on a leap of faith.
– Tim Keller, Reason for God: Belief in an Age of Skepticism, copyright 2008, page xvi
[Philosopher Richard] Rorty and others argue that religious argument is too controversial, but [legal theorist Michael J.] Perry retorts in Under God? Religious Faith and Liberal Democracy that secular grounds for moral positions are no less controversial than religious grounds, and a very strong case can be made that all moral positions are at least implicitly religious. Ironically, insisting that religious reasoning be excluded from the public square is itself a controversial “sectarian” point of view.
– Tim Keller, Reason for God: Belief in an Age of Skepticism, copyright 2008, page 17
Here are the two foundations for our final justification: Christ’s bearing our condemnation in his own flesh (Romans 8:3) and the Spirit working in us an obedient submission to God (Romans 8:4). Both are the reason there is no condemnation (Romans 8:1). These two bases correspond to the two realities to which our works are evidence: We are in Christ and so have died with him in his penal death for us, and his Spirit is in us bearing the fruit of obedience.
– John Piper, The Future of Justification: A Response to N.T. Wright, copyright 2007, page 121
When Paul contemplates the basis of his escape from wrath in his first letter to the Thessalonians, it is precisely to the death of Christ that he looks. In I Thessalonians 5:9-10 he says, “God has not destined us for wrath, but to obtain salvation through our Lord Jesus Christ, who died for us so that whether we are awake or asleep, we might live with him.” In other words, when Paul explicitly contemplates the basis of his escape from wrath in the final day, he does not mention the church planting that God has enabled him to achieve. He mentions the death of Christ.
– John Piper, The Future of Justification: A Response to N.T. Wright, copyright 2007, page 166
Our only hope for living the radical demands of the Christian life is that God is totally for us now and forever. Therefore, God has not ordained that living the Christian life should be the basis of our hope God is for us. That basis is the death and righteousness of Christ, counted as ours through faith alone. On the cross, Christ endured for us all the punishment required of us because of our sin. And in order that God, as our Father, might be completely for us and not against us forever, Christ has performed for us, in his perfect obedience to God, all that God required of us as the ground of his being totally for us forever.
– John Piper, The Future of Justification: A Response to N.T. Wright, copyright 2007, page 184
If we make the mistake of thinking that our works of love (the fruit of God’s Spirit) secure or increase God’s commitment to be completely for us now and in the last judgment, we comprise the very reason that these works of love exist, namely to display the infinite worth of Christ and his work as our all-sufficient sacrifice.
– John Piper, The Future of Justification: A Response to N.T. Wright, copyright 2007, page 185-186
God counts us as having his righteousness in Christ because we are united to Christ by faith alone. That is, we are counted as perfectly honoring and displaying the glory of God, which is the essence of God’s righteousness, and which is also a perfecting fulfilling of the law. This is what God imputes to us and counts us as having because we are in Christ who perfectly honored God in his sinless life. It is not nonsense. It is true and precious beyond words.
– John Piper, The Future of Justification: A Response to N.T. Wright, copyright 2007, page 165