In the daily Mass readings, we're going through some detail-heavy and action-packed parts of the old Testament right now. Prophets are lecturing kings, and God is smiting everyone, practically. Lots of rebellion, haircloth, idolatry and penitence: busy, busy, busy.
We're also going through a lot of teaching from Jesus. How to pray, how to give alms, how to forgive, how to do lots of things with His Spirit. Gentle, stern, glowing words.
The contrast in the two reading streams is interesting: on the one hand, people in the Old Testament just weren't getting it. People in the New Testament weren't getting it, either, but God's response and teaching is different.
In the OT, God asked His people to follow His commandments. When they didn't, God got their full attention, dramatically so. The relationship was sort of immature (no, God was not immature, we were): we misbehave and God yells at us. We do it again, and He yells louder.
In the NT, Jesus, God incarnate, explains it where we can see it. He is the model of ALL love, which, since He is Love, is right. He is the Spouse of our soul, and of the Church. He is our Brother. He refers us to the fatherhood of God. He is our Teacher, our Healer, our Shepherd. Every one of those relationships exist in our own human lives, and He models how we are to handle them. It's a fully-faceted, three-dimensional model that we can turn in our hands and examine.
It's as though the yelling parent God of the OT, now thoroughly exasperated, grabs the SOS pad and the dirty pot, scours it, thrusts it at us, and says "THIS is how you wash a dish!" We have to see it happen to understand it.
The infinite patience and love of God!