In the first reading (Deuteronomy 4:1, 5-9), the teaching of the Commandments and the works of God is bound with the need to keep all of these things firmly in our own minds.
However, take care and be earnestly on your guard
not to forget the things which your own eyes have seen,
nor let them slip from your memory as long as you live,
but teach them to your children
and to your children’s children.
In the Gospel (Matthew 5:17-19), our Lord makes it very clear that teaching and following the Commandments rightly is critical to our relationship with God.
Whoever breaks one of the least of these commandments
and teaches others to do so
will be called least in the Kingdom of heaven.
But whoever obeys and teaches these commandments
will be called greatest in the Kingdom of heaven.
We cannot just dismiss this warning as applying only to those wild liberals who water down Christian moral teaching and excuse every kind of debauchery.
Each of us, as citizens of the Kingdom of God, must follow and teach the commandments of God as completely and as effectively as we can.