Romans 5:20 AMP: But then Law came in, [only] to expand and increase the trespass [making it more apparent and exciting opposition]. But where sin increased and abounded, grace (God’s unmerited favor) has surpassed it and increased the more and superabounded,
Here, the scripture tells us that when sin increases because of the sin-nature man inherited from Satan through the sin of Adam, God‘s grace through the Lord Jesus increases and abounds much more.
Let us recall that God’s grace in Christ Jesus is the unmerited favour of God that causes Him to release eternal life into our spirits on the legal basis of the sufferings, death and resurrection of the Lord Jesus Christ.
This is why it is called the grace of life:
1Peter 3:7 MKJV: Likewise, husbands, live together according to knowledge, giving honor to the wife as to the weaker vessel, the female, as truly being co-heirs together of the grace of life, not cutting off your prayers.
Now, when sin increases, God causes grace to increase even more; what this means practically is that God increases the measure of life He gives to us. This increase in life causes us to have greater wisdom and power to overcome sin.
Now, for this to happen, we have to be honest about our sins by confessing them and forsaking them in our hearts: a determination to overcome them. When we confess our sins, God forgives us and cleanses us from the block the sin substance creates between our spirits and God’s Spirit so that the life of God can flow freely into our spirits:
1John 1:7-10 MKJV: But if we walk in the light, as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin. (8) If we say that we have no sin, we deceive ourselves, and the truth is not in us. (9) If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness. (10) If we say that we have not sinned, we make Him a liar, and His Word is not in us.
As we confess our sins, and then ask for life and pray in the Spirit, God gives us His life and power in a greater measure than we had before, so that we can overcome the power of sin in the air and in our flesh (Eph. 2:2-3) that comes against us.
As this cycle of commission of sin, confession and cleansing of sin, receiving life and praying in the Spirit continues from hour to hour, day to day, week to week, month to month, year to year; you will find that the frequency and gravity of your sins will gradually reduce daily, weekly, monthly and yearly to the point where you rarely ever sin and even when you do, they will not be sins of any serious gravity: like thoughts of foolishness (Pr. 24:9), praying absent mindedly without faith (Rom. 14:23) which you quickly repent of and do not continue in.
Ultimately, as we gradually and sequentially experience cleansing perfection, manifesting perfection and finally permanent perfection our sin-rate will go to zero: a condition in which we never sin, fulfilling:
1John 3:9 AMP: No one born (begotten) of God [deliberately, knowingly, and habitually] practices sin, for God’s nature abides in him [His principle of life, the divine sperm, remains permanently within him]; and he cannot practice sinning because he is born (begotten) of God.
1Thessalonians 5:23 NKJV: Now may the God of peace Himself sanctify you completely; and may your whole spirit, soul, and body be preserved blameless at the coming of our Lord Jesus Christ.
James 3:2 AMP: For we all often stumble and fall and offend in many things. And if anyone does not offend in speech [never says the wrong things], he is a fully developed character and a perfect man, able to control his whole body and to curb his entire nature.
So when iniquity abounds grace does much more abound.
Now, this grace abounds by honesty of heart, which causes God to give us greater measures of life, giving us more light (Dan. 5:4): more of the knowledge and wisdom of God, fulfilling:
2Peter 1:2 KJV: Grace and peace be multiplied unto you through the knowledge of God, and of Jesus our Lord,
We see this truth exemplified in the life of Ahab, one of the Kings of Israel (who was not a good King but who humbled himself when God’s Word of judgment (1 Kgs. 21:27-29) came to him) when God’s grace upon him and the armies of Israel under him was multiplied to enable them overcome (1 Kings. 20:11-29) armies that out-numbered them in ratios of more than 10 to 1 (1 Kgs. 20:15, 29): indeed where sin or problems abound the grace of God much more abounds to overcome them.
2Chronicles 16:9 MKJV: For the eyes of Jehovah run to and fro in all the whole earth to show Himself strong on behalf of those whose heart is perfect toward Him. You have done foolishly in this; therefore from now on you shall have wars.
So, by exercising honesty of heart and practicing righteousness using the blood (1 Jn. 1:7-10, Heb. 13:20-21), the Word (1 Jn. 2:5) and Spirit (1 Jn. 4:12-18) to perfect obedience, you will find that when sin abounds grace will much more abound!