They don't love God because they love themselves and their self-importance more. They don't love their neighbor because they'd rather abuse widows than serve them.
In contrast to them, in Mark 12:41-44, is, of all people, a widow! This widow loves God with all her heart, soul, strength, and mind. She gave a tiny fraction of what the rich were giving, but Jesus says she gave MORE THAN they gave.
How could she? Because she gave sacrificially, from her heart. It wasn't about the money. It's never about the money. She gave a gift of her heart because of her love for God.
We avoid hypocrisy by focusing on our love for God, seeing where that love leads us, and then loving him.
Sermon: How to Love God Without Hypocrisy (Mark 12:38-44)