If we grant this principle you seem to think makes so much sense, then we can safely conclude that the rest of God's laws are also still in force, no? So does Joseph Smith uphold the dietary laws?
Abraham was 400 years prior to the Mosaic Law.
How does this all fit in with adultery? In other words, we have Jesus pointing out that if a woman is divorced, remarriage is tantamount to adultery. Then there's always the Sabbath which most Christians have no problem profaning. Last time I checked, Mormons weren't interested in keeping the Sabbath either.
Cherry pick much?
Just a note here--the testimony of God is that He extended His grace to Abraham because he kept His commandments. Period.
Abraham lived under the gospel--before the Mosaic Law was added. The same gospel which the NT writers testified God's grace was connected to keeping the commandments:
1 John 2:3-4---King James Version (KJV)
3 And hereby we do know that we know him, if we keep his commandments.
4 He that saith,
I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
Matthew 19:16-19---King James Version (KJV)
16 And, behold, one came and said unto him, Good Master,
what good thing shall I do, that I may have eternal life?
17 And he said unto him, Why callest thou me good? there is none good but one, that is, God:
but if thou wilt enter into life, keep the commandments.
18 He saith unto him, Which? Jesus said
, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness,
19 Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself.
1 Corinthians 7:19---King James Version (KJV)
19 Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God.
Revelation 22:14--King James Version (KJV)
14 Blessed are they that
do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city.
John 14:15--King James Version (KJV)
15 If ye love me, keep my commandments.
Revelation 12:17--King James Version (KJV)
17 And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ.
1 John 5:3--King James Version (KJV)
3 For this is the love of God, that we keep his commandments: and his commandments are not grievous.