There are some things that the Scriptures speak of tangentially but are things that generate more than tangential interest. "Who is Satan and where did he come from?" is an example. This combination of sparse Scripture and abundant curiosity is one of the reasons that teachers and students can become embroiled in strange doctrines. It takes maturity to leave such things alone and move on and cherish the substantive subjects. The Scriptures are not there to satisfy our curiosity about evil and its origins, but they are full of God's goodness and a life of faith. The answer to strange doctrine, then, is the correct application of the whole counsel of Scripture:

But we know that the Law is good, if one uses it lawfully, realizing the fact that law is not made for a righteous person, but for those who are lawless and rebellious, for the ungodly and sinners, for the unholy and profane, for those who kill their fathers or mothers, for murderers and immoral men and homosexuals and kidnappers and liars and perjurers, and whatever else is contrary to sound teaching, according to the glorious gospel of the blessed God, with which I have been entrusted. 

I thank Christ Jesus our Lord, who has strengthened me, because He considered me faithful, putting me into service, even though I was formerly a blasphemer and a persecutor and a violent aggressor. Yet I was shown mercy because I acted ignorantly in unbelief; and the grace of our Lord was more than abundant, with the faith and love which are found in Christ Jesus. 

It is a trustworthy statement, deserving full acceptance, that Christ Jesus came into the world to save sinners, among whom I am foremost of all. Yet for this reason I found mercy, so that in me as the foremost, Jesus Christ might demonstrate His perfect patience as an example for those who would believe in Him for eternal life. 

Now to the King eternal, immortal, invisible, the only God, be honor and glory forever and ever. Amen. (1 Timothy 1:8-17) 

There are many evangelical Christians who count the Old Testament as a bad thing. They confidently assert, "We are no longer under the Law but under grace!" Although there is a certain element of truth in the statement, the truth requires more finesse. After all, the promise of the New Covenant as written in Jeremiah is this, "...I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people." (Jeremiah 31:33b). Here Paul says several things:

1. The Law is able to identify sin and to teach truth about God and His paths. The same evangelicals who say "Not Law, but Grace" can often be heard saying or singing, "Thy word is a lamp unto my feet and a light unto my path." This is a quote from Psalm 119 and speaks about the Law. Law is light. It is not darkness. People can use it in dark ways, but that does not extinguish the light. The Law is for sinners because it can tell them of their sin so that they know from what they need to be saved. The problem with Law is not that it is bad, but that it cannot impart righteousness. It can tell me that I am jealous and murderous, it cannot make me be a loving and generous person.
2. Paul counts himself as the chief of sinners. He uses the present tense when he says this. If Paul, near the end of his days, can call himself the chief of sinners, then who am I to say that the Law has no benefit to me.
3. Acknowledging sin is the means by which we find mercy. Law and Grace are partners.

Grace is not a New Testament concept. The Old Testament word "chesed" which is often translated as "loving-kindness" would call grace a synonym. Faith is not a New Testament concept either, which Paul makes clear in Romans, "For what does the Scripture say? 'Abraham believed God, and it was credited to him as righteousness.'” (Romans 4:3) The New Covenant is about the giving of the Holy Spirit and free access to God by virtue of the superior quality of Jesus death over the death of goats and bulls.

The contrast between what the Law reveals about mankind and the grace and mercy that flow from the work of Jesus Christ move Paul to praise. 

By avoiding the commands of God and focusing only on grace, we cannot have a complete picture of who He is and who we are. we use the Law illegally when we use it to justify ourselves and condemn others. Rather, if the Law condemns us, and we seek mercy, grace, and power by the Holy Spirit, the Law becomes written on our hearts and we can move in the fruit of the Spirit against which there is no Law:

But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. (Galatians 5:22-23)

This is cause for praise.

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