The principles upheld in this book are extremely important today, for as the title page notes "When nations are to perish in their sins, 'Tis in the Church the leprosy begins." Begg lays his foundations in the second commandment and deals with all man-made innovations in the worship of God. The four types of innovators exposed are especially interesting, being: 1.) the presumptuous and blasphemous innovator; 2.) the popularity-hunting innovator; 3.) the politic and scheming innovator; 4.) the asthetic innovator. Women preachers, drama, dance and numerous other modern inventions in public worship would all be rejected outright if these Biblical principles were faithfully followed. Herein we also see why those holding to the Scriptural law of worship and the Westminster Confession of Faith must reject musical instruments in public worship just an unbiblical innovation - a resurrecting of the abrogated ceremonial law - and thus a denial of the finished work of Christ.