The spirit of complaint is born out of an unwillingness to trust God with today. Like the Israelites, it means you are spending your time looking back toward Egypt or wishing for the future all the while missing what God is doing right now.
Discontent
Arthur W. Pink
Satan is ever seeking to inject that poison into our hearts to distrust God’s goodness – especially in connection with his commandments. That is what really lies behind all evil, lusting and disobedience. A discontent with our position and portion, a craving from something which God has wisely held from us. Reject any suggestion that God is unduly severe with you. Resist with the utmost abhorrence anything that causes you to doubt God’s love and his lovingkindness toward you. Allow nothing to make you question the Father’s love for his child.
Madeleine L’Engle
No long-term marriage is made easily, and there have been times when I’ve been so angry or so hurt that I thought my love would never recover. And then, in the midst of near despair, something has happened beneath the surface. A bright little flashing fish of hope has flicked silver fins and the water is bright and suddenly I am returned to a state of love again — till next time. I’ve learned that there will always be a next time, and that I will submerge in darkness and misery, but that I won’t stay submerged. And each time something has been learned under the waters; something has been gained; and a new kind of love has grown. The best I can ask for is that this love, which has been built on countless failures, will continue to grow. I can say no more than that this is mystery, and gift, and that somehow or other, through grace, our failures can be redeemed and blessed.