Instead of speaking of subjective or objective moral foundations, the Christian faith brings an intrinsic aspect of morals and ethics. This perhaps most clearly shown in the following:
Galatians 5:19-26 (KJV)
Gal 19 Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness,
20 Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies,
21 Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God.
22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23 Meekness, temperance: against such there is no law.
24 And they that are Christ’s have crucified the flesh with the affections and lusts.
25 If we live in the Spirit, let us also walk in the Spirit.
26 Let us not be desirous of vain glory, provoking one another, envying one another.
These verses show that a Christian is called to reject the works of the flesh and by rebirth bring forth the fruits (or attributes) of the Spirit. Once this is done, there is no law that can work against us.
Thus the question should be stated otherwise - how does a human being become a Christian? Once this is answered, the rest of the matter becomes clear.