To understand the importance of loving the Lord with all your heart, the first commandment and then the second is to love thy neighbour.
We must turn to the book of Mark 12:30-31 And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment. And the second is like, namely this, Thou shalt love thy neighbour as thyself. There is none another commandment greater than these.
In this so-called modern world, we tend to love God when everything is going well. But, to love God with your heart means to love God with your emotions. Praising him with your gratitude, happiness and smile is easy when things are going well. However, ALL your heart means at ALL times, even when God seems quiet. Even when he says wait. And even when he says no. And, yes, also when bad things happen. Continuing to love God even when bad things happen or when good things don’t happen is key to a life of contentment. As a child of God, the Devil is going to find ways to make your life miserable. You have to see through that unfortunate circumstance to the God who wants to comfort you and will never leave you nor forsake you.
To Love God at all times is a day-to-day learning process. We learn more and more how to do it and keep on doing it a little each day. Until soon you can say, I am content no matter what. I can live on almost nothing, and I can live with everything. The secret of living in every situation is to remember that I can do everything, I can live through anything, and I can even overcome through Christ who gives me strength, sustenance, and courage.