He was also a famous writer and speaker. In a conference address called "Jealousy for God in a Godless World", Muller made these remarks, which are quite timely today.
As we are drawing nearer and nearer the close of the present dispensation, spiritual darkness, departure from the Holy Scriptures, and consequent ungodliness, we have reason to believe, will increase more and more, though coupled with a form of godliness (see 2 Timothy 3.1–5). Therefore the path of a true disciple of the Lord Jesus will become more and more difficult; but for this very reason it is of so much the more importance to live for God, to testify for God, to be unlike the world, to be transformed from it. If we desire that thus it may be with us, it is needful that we give ourselves to the prayerful reading of the Holy Scriptures with reference to ourselves. The Bible should be to us the Book of books; all other books should be esteemed little in comparison with the Bible. But if this is not the case, we shall remain babes in grace and knowledge.
And now, beloved fellow-disciples, how many of us are in heart purposed to live for God, to be zealous for God, and to be truly transformed from the world? We have but one brief life here on earth. The opportunities to witness for God by our life will soon be over; let us therefore make good use of it. Let none among us allow his life, nor even a small part of it, to be wasted, for it is given to us to be used for God, to His glory, in this godless world.
Jehovah Magnified: Addresses
"Jealousy for God in a Godless World"