In addition to the central contention that choice of the authentic or the Christian life is impossible absent God as an outside force available to and interacting with humans, Macquarrie integrates several other Christian themes into his work. One is the power of and importance of grace, which is the means by which God saves the previously nonbelieving human on that human’s acceptance of God’s existence and importance and decision to live a Christian life. Macquarrie accurately notes that there is no analogous belief or phenomenon in Heidegger’s existentialism and that grace exists independently from humans and is not in humans’ control, but is an action, an event, in which God powerfully participates.
Related to grace as a Christian theme in Macquarrie’s work are the historic, saving events that make it possible for humans to receive grace. These saving events, or mighty acts in Macquarrie’s terms, which came into the human situation solely because of God, include Jesus’ conception, his incarnation of God, his birth and life, his crucifixion, and his resurrection. Macquarrie synthesizes these mighty acts under the cross as symbol and contends that whatever happened specifically at the time of these events, all that believers need to know (and all they probably can know) is that, at that time in history, God directly intervened in earthly life and thereby provided believers with the avenue by which they can attain everlasting life, that is, by accepting God’s existence and intervention, whatever the specifics, and by living a life of faith, hope, joy, peace, freedom, and especially love (and even love of nihilists like Heidegger).