To adore God in spirit and in truth means to adore Him as we should. Because God is a Spirit, He must be adored in spirit. That is to say, we must worship Him with humble, sincere love that comes from the depth and center of our souls. Only God can see this adoration, which we must repeat until it becomes part of our nature, as if God were one with our souls and our souls were one with God. Practice will demonstrate this.
Second, to adore God in truth is to recognize Him for what He is and ourselves for what we are. Adoring God in truth means that that our hearts actually see God as infinitely perfect and worthy of our praise. What man, no matter how little sense he may have, would not exert all his strength to show his respect and love of this great God?
Third, to adore God in truth is to admit that our nature is just the opposite of His. Yet, He is willing to make us lie Him, if we desire it. Who would be so rash as to neglect, even for a moment, the respect, the love, the service, and the continual adoration that we owe Him?