All we have to do was remain in Him. The pastor isn't wrong. He's directly quoting scripture.
We put the burden on ourselves. That sounds odd and silly doesn't it? But here is that rephrased - we want to do well for ourselves. Now that doesn't seem so ludicrous, but rather very practical. Who wants to do poorly for themselves? Don't all of us want to be at the end of a conversation like "Oh Sarah? She's doing real well for herself." That burden just slips in, just like that.
"The kingdom of heaven is like treasure hidden in a field. When Sarah found it, she hid it again, and then in her joy went and sold all she had and bought that field.Oh Sarah? Well, she's crazy, but she's found something that she really cares about.