This open letter from G. Vogel, supported by brothers from several countries, seriously warns against the main new doctrines advanced by W.J. Ouweneel, in particular: defilement (limited to "fundamental" evil, with accusation of the "chain of defilement"), independence ("partial" autonomy of local assemblies), and "biblical" ecumenism. In passing, the author addresses the important question of prayers to the Holy Spirit. He also denounces the use of philosophical arguments, in themselves clearly contrary to the Word of God.