The thought which we have been pursuing leads us to a truth of major importance: if God is thus in earnest, believing in man's possibilities and laboring for them, then he cannot be known by anyone who does not share his purpose and his labor. _Action is a road to knowledge and some things never can be known without it._ If one would know the business world, he must be an active business man; no amount of abstract study and speculation can take the place of vital participation in business struggle. The way to understand any movement or enterprise is to go into it, share its enthusiasms and hopes, labor sacrificially for its success, bear its defeats as though they were our own, and rejoice in its achievements as though nothing so much mattered to our happiness. Such knowledge is thorough and vital; when one who so has learned what war is, or the missionary enterprise, or the fight against the liquor traffic, stands up to speak, a merely theoretical student of these movements sounds unreal and tame. If therefore God is earnest Purpose, with aims in which he calls us to share, no one can thoroughly know him merely by _thinking_; he must know him by _acting_. =But he that doeth the truth cometh to the light, that his works may be made manifest, that they have been wrought in God.--John 3:21.= =Jesus therefore answered them, and said, My teaching is not mine, but his that sent me. If any man willeth to do his will, he shall know of the teaching, whether it is of God, or whether I speak from myself.--John 7:16, 17.= Many people endeavor to reach a satisfactory knowledge of God by clarifying their thought and working out a rational philosophy. But, by such intellectual means alone, they could not gain satisfactory knowledge of so familiar a thing as home life. To know home life one elemental act is essential: get into a home and share its problems, its satisfactions, and its hopes. So the most adequate philosophy by itself can bring no satisfactory knowledge of God; only by working with God, sharing his purposes for the world, sacrificially laboring for the aims he has at heart can men know him.