Did Jesus speak before the cross? Yep, everything He said up to His ressurrection. Yet Jesus only covered the moral law that would be carried over into the New Covenant. It was God's moral law He used when He rebuked & corrected others. Everything He taught was principles of the Kingdom.
Historical context to prove His identity as Messiah, facts & principles of the Kingdom, All was either to or for us. Observances in the OT weren't to us to follow, yet were to us to read & understand how they all pointed to Christ & had their fulfillment in Him. They are necessary
to us for various reasons, not just to obey them.
Acts 1
1 The first account I composed, Theophilus,
about all that Jesus began to do and teach, 2 until the day when He was taken up to heaven, after He had by the Holy Spirit given orders to the apostles whom He had chosen. 3 To these He also presented Himself alive after His suffering, by many convincing proofs, appearing to them over a period of forty days and speaking of the things concerning the kingdom of God. 4 Gathering them together, He commanded them not to leave Jerusalem, but to wait for what the Father had promised, “Which,” He said, “you heard of from Me; 5 for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.”
Why did Luke write this? Because the Holy Spirit led/told him to. It was to the church, & it was for the church.
Don't believe me?
1 Peter 2:21For you have been called for this purpose, because Christ also suffered for you,
leaving you an example, so that you would follow in His steps,
22HE WHO COMMITTED NO sin, NOR WAS ANY DECEIT found IN HIS MOUTH;
23[x]and while being abusively insulted, He did not insult in return; while suffering, He did not threaten, but kept entrusting
Himself to Him who judges righteously;
24and He Himself
[y]brought our sins in His body up on the
[z]cross, so that we might die to
[aa]sin and live for righteousness; by His
[ab]wounds you were healed.
25For you were continually straying like sheep, but now you have returned to the Shepherd and
[ac]Guardian of your souls.
Jesus was/is:
- A perfect Lamb of God
- A perfect Messiah
- A perfect King
- A perfect example to follow in all holy living
So much so that He said: Matt 16:
24Then Jesus said to His disciples, “If anyone wants to come after Me,
he must deny himself, take up his cross, and follow Me.
25For whoever wants to save his
[y]life will lose it; but whoever loses his
[z]life for My sake will find it.
If there was something that Jesus said that wasn't necessary for the church to see/understand and/or follow, He never would have said it.