Hebrews 8:6-13 / Mark 3:13-19
To be able to put something into a container, there are two obvious requirements - the container must not be full, and there must be at least some space to put that something in.
Similarly, to write something on a piece of paper, there must be a space in the paper to write, and also that the paper cannot have too amny things written on it such that a new addition becomes lost in that overwhelming content.
If that is the case, the same could be said of the mind and heart. To put something into the mind, it must be clear enough to receive it. And for the heart to accept something, it must be open to it.
In the 1st reading, the Lord said that He will make a new covenant with the House of Israel. He will put His laws into their minds and write them in their hearts.
And that covenant is this - The Lord declared that He will be their God and they shall be His people.
That covenant is renewed everyday with us especially in the Eucharist. But we have to clear our minds in order to understand what the Lord wants of us and to cleanse our hearts in order to receive the love that He wants to fill us with.
And just as Jesus called the twelve, Jesus is also calling us to offer to Him our minds and hearts.
May our minds not be distracted, and may our hearts be pure, so that our faith in God will be strengthened and that others will see us as the people of God.