Why do we – Follow the New Testament?

Bible teaches that the new testament, and ONLY the new testament, is where to look for God's will for us today.

The old covenant starts with "IF" (it was conditional from day one) - Exodus 19:5
The old covenant was ONLY with Israel - Exodus 19:6
(although other nations were still required to obey God (Assyria in Jonah 3 ) and knew of His Moral laws (Egypt in Genesis 20:1-6 ))
Israel broke the covenant - Jeremiah 31:32
God said He'd make a NEW covenant - Jeremiah 31:31
Jesus came to FULFIL the old covenant - Matthew 5:17,18 - which He did – Luke 24:44

Bible says THAT the old covenant was taken away:

"ye are become dead to the law" -Romans 7:4
"vanish away" - Hebrews 8:13
"He taketh away the first, that He may establish the second" - Hebrews 10:9

Bible says WHY the old covenant was taken away:

It was something that was going to be fulfilled - Matthew 5:18
New covenant had better promises - Hebrews 8:6
Foretold of a prophet better than moses that the people MUST hear - Deuteronomy 18:15-19
Old covenant not faultless -Hebrews 8:7
Old testament sacrifices could not take away sin - Hebrews 10:4
A new priesthood required a new law - Hebrews 7:12
The old covenant had a job that it did (bring us to Christ) - Galatians 3:24
Having done its job, we're no longer under it - Galatians 3:25

Bible says WHEN the old covenant was taken away:

Jesus nailed it to the cross - Colossians 2:14

Bible says WHEN the NEW covenant was in force:

After the death of the testator - Hebrews 9:16,17

What does the bible say the old covenant was there FOR if it was taken away?

It was a shadow of things to come - Hebrews 10:1 (we can better understand the concepts of sacrifice-for-sin, scapegoat, being separate, priesthood, doing-things-according-to-the-pattern, God-keeps-His-promises, etc.)
For our learning - Romans 15:4
Examples to us to learn from - 1 Corinthians 10:11
Because of transgressions - Galatians 3:19 - *till* the seed should come
To bring us to Christ - Galatians 3:24

What does the bible say about trying to justify your beliefs/practices by looking at what the old covenant said?

If you try to do ANY of the old covenant you're obligated to do ALL of it - Galatians 5:3
If you offend in one point of the law you're guilty of all - James 2:10
Christ is useless to you, you are fallen from grace - Galatians 5:4

What about the ten commandments?

ALL of the ten commandments are RESTATED in the NEW testament (except one), some with even more restriction than the original. i don't commit adultery, murder, or steal, etc. today, not because it would violate the ten commandments, but because it would violate the teachings of the new testament.
I. no other gods before Me - Matthew 4:10
II. no idols - 1 Corinthians 10:14
III. not take name of Lord God in vain - Colossians 3:8
IV. keep sabbath holy - NOT restated in the new testament - the Christians met on the first (not the seventh) day of the week - Acts 20:7
(note that 'the sabbath' is *not* 'just another name for the first day of the week' - they are *separate* days- Matthew 28:1 )
V. honor father and mother - Ephesians 6:1,2
VI. not kill - Mathewt 5:22
VII. not commit adultery - Matthew 5:28
VIII. not steal - Ephesians 4:28
IX. not bear false witness - Ephesians 4:25
X. not covet - Ephesians 5:3o