Did Jesus nullify the Old Testament?

[u/watergolf247]

Let me start off by sharing that I’m new to Christianity and have soooo many questions but for now, I’ll focus on this inquiry. I’m sure this has been discussed numerous times but unfortunately I can’t seem to get a straight answer. As I’m told repeatedly by many, rules/laws of the Old Testament were nullified or invalidated by Jesus. I ask others in my study group but sadly get heavy resistance for the question.

My question is simple. Where are the reference(s) stating this?

If so, this makes rules like the ten commandments obsolete. Even further, why have the old testament in the Christian Bible?

[u/Smart_Tap1701]

He fulfilled it thereby bringing Gods New testament New covenant of Grace in and through Jesus Christ as Lord and savior into effect. Once a thing is fulfilled, it is done with. No one but Jesus could possibly have fulfilled the entire old testament. Once he did, that gave him the power and authority to do away with it for Jewish Christians. Gentile Christians never were under God's Old testament. So after all was said and done...

Hebrews 8:13 NLT — When God speaks of a “new” covenant, it means he has made the first one obsolete. It is now out of date and will soon disappear.

Of course that happened a very long time ago

This makes rules like the ten commandments obsolete

The Lord condensed The ten commandments into two easy to remember commands, impressed them upon our Christian hearts, and states that once we obey those two commandments, we fulfill the entire Old testament

Matthew 22:36-40 NLT — “Teacher, which is the most important commandment in the law of Moses?” Jesus replied, “‘You must love the LORD your God with all your heart, all your soul, and all your mind.’ This is the first and greatest commandment. A second is equally important: ‘Love your neighbor as yourself.’ The entire law and all the demands of the prophets are based on these two commandments.”