Love in us is a passion of the soul, and being such, is subject to ebb and flow, and to be extreme both ways. For whatever is a passion of the soul, whether love or hatred, joy or fear, is more apt to exceed, or come short, than to keep within its due bounds.
In the arena
Left to itself, your love for God, for your wife, for your kids will swing between fire and frost. The question isn't whether it will. It's what you do when it does.
Pick one person you love but have been coasting with. Send them a text, write a note, or sit down across from them and say something specific you are thankful for. Ground the love in something concrete so it has weight when the feeling is low. Make a commitment to them when the feeling is high, and be disciplined to follow through when the feeling is low. Love that endures is love that acts, especially on the days it doesn't feel like it.