Our next Bavinck quote is an illustration of how two things (or in this case two worldviews) can appear to be mutually exclusive, and yet both actually serve to support the same belief (from two different angles).
Running along parallel lines with Pietism was rationalism. Both –each in its own way – undermined the authority of orthodoxy, by transferring the point of gravity to the human subject. (Reformed Dogmatics, Volume 1, page 162).
Perhaps it would be best to begin by defining these different worldviews. Jonathan N. Gerstner (son of his more well known father, John H. Gerstner) gives us a succinct definition of pietism as that which “implies an exclusive concern about one’s inner life at the expense of concern about the society around on” (The Thousand Generation Covenant). Please note that the criticism here is not about a desire for piety or striving for personal holiness as it is so much about it being defined as the sine qua non of Christian life, while downplaying or even ignoring the need for Christian witness to the world around us (see Matthew 5:16). As a result, the Christian life begins to revolve around the self, instead of God and neighbour.
Similarly, as Bavinck notes, rationalism is also about ‘the self’ for rationalism is when “the objective world [is] directed in whole or in part in accordance with the human mind” (Reformed Dogmatics, Volume 1, page 219). Thus rationalism arises as an attempt to judge all truth claims through oneself and to reject all truth claims that do not make sense to oneself. Similar to pietism, we (Bavinck and I!) do not reject rational thought or logic themselves, but we are rejecting the idea that man, unaided by anything other than his own mind, can achieve and maintain the highest form of knowledge and wisdom (see Proverbs 1:7).
Thus the strange relationship and bond these two (seemingly) contradictory worldviews possess. That is, although pietism is founded on a Christian foundation and expressed in Christian ways, and rationalism is founded on deism or even atheism and often (if not always) expressed in ways that are antithetical to Christian foundations, they both serve the same goal or person: ‘me’ or the self. The starting point, or that around which everything revolves (“gravity” as Bavinck says), of both worldviews is man, and not God.
And as Bavinck notes, there is a grave result to these starting points: namely that orthodoxy or ‘right doctrine’ is undermined by this shift in our thinking. For as man becomes the centre or the ultimate measure of all things, orthodoxy cannot stand. For orthodoxy (and orthopraxy or right living) rest on God as the centre.
Jack London said it well: that the fashion of the human is to make “of himself a yardstick with which to measure the universe.” (The Apostate) which, of course, excludes God or at least relegates Him to the boundaries of the universe we have created in our and hearts. Thus both the pietist and the rationalist begin to chop and hack away at all that does not fit with their predetermined mindset. If it doesn’t help me (pietist) or it doesn’t make sense to me (rationalist) then be gone! If, for example, justification by faith impedes my sanctification because I am looking to Christ to save me (pietist), or if the resurrection doesn’t make sense (rationalist), then I no longer need these doctrines to live right in this world. And the historical Christian faith is soon lost in the shuffle as everything, sooner or later, is oriented around ‘me’.
To conclude, I simply want to say that this is a lesson for us as Christians: that is, just because we are professing Christ does not make everything we say and do sanctified and holy. Furthermore, sometimes even noble (pious) pursuits end up pushing the essentials to the periphery. So what we believe and do should be under constant scrutiny by ourselves but not all by ourselves and not for ourselves.
We must ask ourselves: have we adopted a worldview, even in the name of Christ, that tells others more about the Christian than their Lord and Saviour? Are we believing and acting out of a concern to glorify God in all that we do, or are we really just bringing attention to ourselves?
Romans 11:33-36 “Oh, the depth of the riches both of the wisdom and knowledge of God! How unsearchable are His judgments and His ways past finding out! ‘For who has known the mind of the LORD? Or who has become His counselor?’ ‘Or who has first given to Him And it shall be repaid to him?’ For of Him and through Him and to Him are all things, to whom be glory forever. Amen.
 I am not implying that man cannot know anything apart from faith in God. Many people in this world know and profess things that are true without professing faith in a personal Creator. I am, however, implying that man cannot know anything apart from the existence of God so that all knowledge we have is ultimately derived from God. One can claim that any truth they possess has been achieved apart from God (in their minds) but it is ultimately futile and self-refuting to do so (a subject for another time).