This is from Sub-Chapter 2 [Fiqh-u `Adhamat-ir-Rabb: Fiqh of the Grandeur of ar-Rabb (The Master)] of Chapter 1 of the book.
ولا قدر الله حق قدره من يعامل الخلق بأفضل ما يقدر عليه، ويعامل الله بأهون ما عنده، إن قام في خدمة من يحبه من البشر قام بالجد والاجتهاد والإتقان، وإن قام في حق ربه قام قياماً لا يرضاه مخلوق من مخلوق مثله، وبذل له من ماله ما يستحي أن يعطيه مخلوقاً مثله.
[Roughly translated:] “And he did not value Allah as he should have, one who treats the people in the best way he can, and treats Allah with the least of what he can (or has). If he stands in servitude to the one he loves from the men, he stands with earnestness, diligence and excellence. And if he stands to fulfill the right of his Lord, he stands with a standing that would not please even a creation like him. And he spends for Allah from his wealth what he would be ashamed to spend for others.”
Is it not true? No matter how much we claim to love Allah the ‘most’, we always fall short in doing the ‘best’ for Him. There’s always someone or something more important than Him. There’s always someone or something that needs our wealth/attention/servitude more than Him. Astaghfirullah.