It is also a key to understanding the whole purpose and intent of the New Covenant. God did not establish the New Covenant to abolish His laws, which are holy, just and good (Romans 7:12 Romans 7:12Why the law is holy, and the commandment holy, and just, and good.
American King James Version×). He established it to remedy the flaw that was in the people (Hebrews 8:8 Hebrews 8:8For finding fault with them, he said, Behold, the days come, said the Lord, when I will make a new covenant with the house of Israel and with the house of Judah:
American King James Version×)—the weakness, disobedience and lack of faith inherent in all of us that leads us to sin (Romans 3:10-18 Romans 3:10-18  As it is written, There is none righteous, no, not one:  There is none that understands, there is none that seeks after God.  They are all gone out of the way, they are together become unprofitable; there is none that does good, no, not one.  Their throat is an open sepulcher; with their tongues they have used deceit; the poison of asps is under their lips:  Whose mouth is full of cursing and bitterness:  Their feet are swift to shed blood:  Destruction and misery are in their ways:  And the way of peace have they not known:  There is no fear of God before their eyes.
American King James Version×). Through His Spirit, God empowers us to develop holy, righteous character and resist temptation and the pulls to sin.
With God's Spirit at work within us, God's wonderful promise of the New Covenant in Jeremiah 31:33-34 Jeremiah 31:33-34  But this shall be the covenant that I will make with the house of Israel; After those days, said the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
 And they shall teach no more every man his neighbor, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them to the greatest of them, said the LORD: for I will forgive their iniquity, and I will remember their sin no more.
American King James Version×can be fulfilled: "I will put My law in their minds, and write it on their hearts; and I will be their God, and they shall be My people. No more shall every man teach his neighbor, and every man his brother, saying, ‘Know the Lord,' for they all shall know Me, from the least of them to the greatest of them, says the Lord. For I will forgive their iniquity, and their sin I will remember no more."
Receiving the Holy Spirit gives a Christian the spiritual power needed to live a godly life. It helps provide the motivation and strength that make it possible for us to be able to obey God's commandments, make right choices, overcome and persevere (Romans 5:5 Romans 5:5And hope makes not ashamed; because the love of God is shed abroad in our hearts by the Holy Ghost which is given to us.
American King James Version×; Romans 8:26 Romans 8:26Likewise the Spirit also helps our infirmities: for we know not what we should pray for as we ought: but the Spirit itself makes intercession for us with groanings which cannot be uttered.
American King James Version×; Romans 12:2 Romans 12:2And be not conformed to this world: but be you transformed by the renewing of your mind, that you may prove what is that good, and acceptable, and perfect, will of God.
American King James Version×; Philippians 2:5 Philippians 2:5Let this mind be in you, which was also in Christ Jesus:
American King James Version×; 2 Peter 1:3-4 2 Peter 1:3-4  According as his divine power has given to us all things that pertain to life and godliness, through the knowledge of him that has called us to glory and virtue:  Whereby are given to us exceeding great and precious promises: that by these you might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
American King James Version×).
How great is our loving God and Father who has made all things possible through His Son Jesus Christ! (Matthew 19:26 Matthew 19:26But Jesus beheld them, and said to them, With men this is impossible; but with God all things are possible.
American King James Version×). His work within us is accomplished through the greatest gift that could ever be made available for human beings: the power, love and mind of Christ through the Spirit of God at work in our lives.