What is the servant's role in marriage, knowing that it is among Allah's predetermined decrees at a specific time?

Belief in divine decree does not mean abandoning means; rather, it is one of its requirements. Allah commanded us to employ means, and these means do not yield results except by His permission. Abandoning means is a form of helplessness that contradicts reliance (tawakkul), which is the heart's dependence on Allah while actively pursuing means. Neglecting them detracts from tawakkul.