"What availeth a great dispute about abstruse and obscure matters for the not knowing which, we shall not be questioned at the day of judgment? It is a great folly for us to neglect things profitable and necessary, and willingly to busy ourselves about those which are curious and hurtful. "We have eyes and see not."  

Many make it more their study to know than to live well, therefore are they often deceived, and bring forth none or very little fruit. Oh, if men would use as much diligence in rooting out vices and planting virtues as they do in proposing questions there would not be so great evils committed, and scandals among the people, nor so much relaxation in the churches. 

Truly, when the day of judgment comes, we shall not be asked what we have read, but what we have done; not how learnedly we have spoken, but how religiously we have lived.
How many perish in the world through vain learning, who little care for the service of God! And because they chose rather to be great than to be humble they are lost to their own imaginations."  
Thomas A. Kempis, "The imitation of Christ." The most read devotional book in the world.