To be sure, there are differences of character, both personal and national, between the two great reformers, which account for a somewhat different development of their churches. In Luther's piety the joyful experience of salvation brings in a happy note; the children of God praise his love and grace. In Calvin's devotion the feeling prevails that God's majesty is above all creatures and that his holy will is the supreme rule for our life. Religion with Luther is bright and cheerful, whereas with Calvin it has a darker tinge. But both are building on the same foundation and with the same end in view: from salvation to salvation, from grace to grace. The difference is but one of attitude toward the present life. The difference finds its best expression in a varying use of the phrase Word of God. Both, of course, believed in an historical revelation of God to mankind, and they were convinced that this revelation was to be found in the holy Scriptures. God had spoken through his prophets; he had given his promises to his people; he had sent his Son and had fulfilled his promises through him. All this was to be found in the Bible and only in the Bible. The reformers refused the authority of tradition, just as they declined to acknowledge the present individual inspiration of enthusiasts, or "Schwarmgeister," as Luther contemptuously called them. It was in the Bible that Christianity had to look for all necessary information about God and salvation. And yet Luther, when using the expression Word of God, scarcely thinks of the written book. It is the living word as represented by the preaching of the prophets and the apostles, and perpetuated by the preaching of the ministers of the church. It is to him not a formal authority but an energising inspiration. Not everything in the Bible is authoritative, merely by the fact that it stands in the Bible; only what witnesses to Christ is authoritative and is to be taken as the Word of God. On the other hand, Zwingli and Calvin frequently use the term Word of God when speaking of the holy Scriptures themselves. It is characteristic that the reformed churches of Switzerland felt it their duty to fix the exact number of writings included in this Word of God, just as the Roman Catholic church did at the Council of Trent, while no Lutheran creed ever defines the exact content of the Bible. To the former it was a book of law, to the latter a book of inspiration.