Mercy, not sacrifice

I am going to preach Matthew 12:1-14 today.
Jesus quoted Hosea 6:6 two times: Matthew 9:13 and Matthew 12:7. There, we read:
For I desired mercy, and not sacrifice; and the knowledge of God more than burnt offerings.

This verse is connected to Mark 12:33

And I know it is important to love him with all my heart and all my understanding and all my strength, and to love my neighbor as myself. This is more important than to offer all of the burnt offerings and sacrifices required in the law.”

Let the preacher preach to himself first, and then to others.
The way I spend my time shows a lot about how I love the Lord and love others. Do I seek to know the Lord and do I have mercy?
I attended the church since childhood. In general, I saw the Lord as the universe's Commander who created a lot of rules: don't do this or that. If you sin, you are in hell unless you repent.
How should I rest in the Lord with such thoughts?
Although I had to believe that the Lord is good and his mercy endures forever, in fact, the Lord was a rigid commander. I was very prompted to think: ‘Master, I knew that you were a harsh man, reaping where you did not sow, and gathering where you did not scatter seed" Matt25:24
In order to please him, I had to constrain myself in many aspects and in doing so, I was ready to judge others who didn't constrain themselves; that is: I was a religious man, but without mercy. But, I still hadn't peace in my heart because the Lord was like a lion, eager to attact me.
As I began to understand that I belong to the Lord despite all my sins, I began to rest on him. I believe that I began to love more others and be more merciful to others because the Lord has been merciful to me.
Therefore, I know that I am in the Way to know the Lord more and to love others more. Even though I enjoy staying with believers, there are many and many times that I prefer to stay alone. Am I wrong? Maybe. These days, I am spending my time thinking about money allocation, much more than putting my thoughts in the Lord. Am I wrong? Maybe. Anyway, I am quite sure that the One who began the work on me, will complete it.
In today's sermon, Jesus is defending his disciples that were accused of not keeping the Sabbath because they caught grain and were eating it. Jesus said:

7 But if you had known what this means, ‘I desire mercy and not sacrifice,’ you would not have condemned the guiltless. 8 For the Son of Man is lord of the sabbath.”

Jesus is saying this to me, too; mainly when I saw the Lord as a lion who was eager to send me to hell by not tithing, for example. I didn't understand that the Lord desire mercy, because for me, the Lord was nor merciful and the only way to please him was by sacrifice. So, in the same way, I was eager to condemn the guiltless.
The Son of Man is Lord of the Sabbath, he is the Lord of the tithing, he is the Lord of any ceremonial law and I love him more than the ceremonial law.