It was the sacrificial temple ordinance laws that Christ fulfilled for the remission of sins. This represents all of the things that the Levitical priesthood was responsible for in the Old Covenant. Love is now the law described first in Leviticus 19 and Deuteronomy 6 and confirmed by Christ. Through Christ Jesus, this capability is given for us to fulfill. Of course there are more instructions defining God's agape love in both Old and New Testament laws that are our response because He loved us first.
It was the entire Law that Jesus fulfilled perfectly on our behalf; because we are imperfect and unable to keep it ourselves.
Ro 8:1-11
There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
3 For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
4 That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
5 For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
6 For to be carnally minded is death; but to be spiritually minded is life and peace.
7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
8 So then they that are in the flesh cannot please God.
9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
10 And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness.
11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
KJV
Ro 8:1-11
There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
3 For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
4 That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
5 For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
6 For to be carnally minded is death; but to be spiritually minded is life and peace.
7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
8 So then they that are in the flesh cannot please God.
9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
10 And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness.
11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
KJV
I'll quote the "love they neighbor" instructions found in Leviticus 19:9-18 just to make this post short, even though I have read more about the way I should act. I feel that our part is to love with accountability defined in the law.
[SUP]9 [/SUP]And when ye reap the harvest of your land, thou shalt not wholly reap the corners of thy field, neither shalt thou gather the gleanings of thy harvest.
[SUP]10 [/SUP]And thou shalt not glean thy vineyard, neither shalt thou gather every grape of thy vineyard; thou shalt leave them for the poor and stranger: I am the Lord your God.
[SUP]11 [/SUP]Ye shall not steal, neither deal falsely, neither lie one to another.
[SUP]12 [/SUP]And ye shall not swear by my name falsely, neither shalt thou profane the name of thy God: I am the Lord.
[SUP]13 [/SUP]Thou shalt not defraud thy neighbour, neither rob him: the wages of him that is hired shall not abide with thee all night until the morning.
[SUP]14 [/SUP]Thou shalt not curse the deaf, nor put a stumblingblock before the blind, but shalt fear thy God: I am the Lord.
[SUP]15 [/SUP]Ye shall do no unrighteousness in judgment: thou shalt not respect the person of the poor, nor honor the person of the mighty: but in righteousness shalt thou judge thy neighbour.
[SUP]16 [/SUP]Thou shalt not go up and down as a talebearer among thy people: neither shalt thou stand against the blood of thy neighbour; I am the Lord.
[SUP]17 [/SUP]Thou shalt not hate thy brother in thine heart: thou shalt in any wise rebuke thy neighbour, and not suffer sin upon him.
[SUP]18 [/SUP]Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the Lord.
This is a small part of what hangs on the law of love as I believe in the fulfillment of Christ for salvation. Through Christ, I think what I quoted, from the law, is possible to adhere to by His dwelling Spirit. We should practice the principles which leads to having the "mind of Christ."
"But Jesus beheld them, and said unto them, With men this is impossible; but with God all things are possible." Matthew 19:26