There’s an inner and external Christian life. The inner life is the way to attain true holiness and immortality in God. When Paul the apostle wrote to encourage Christians living in Corinthians in the 1st century, he said….

Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal. (2Corinthians4:16-18)

This scripture absolutely explains what inner life in Christ represents. Inner life entails daily cleansing “purification” of our inward man through the internal truth; the heavenly realities perceived through our inner sight or the eyes of the spirit. Inner life works with inward witnessing of the Holy Spirit (Romans8:16). If you’re living an inner Christian life, or living by the Spirit, you’ll discover there are internal laws of God which can be hidden from a non spiritual person because those laws aren’t written plainly in the bible. There are many unlawful deeds “sin” that aren’t plainly recorded in the book of law; the original Hebrew Tanakh “the Hebrew Bible” recorded in Torah (Genesis –Deuteronomy) is only 613 commandments (mitzvoth) including the “10 Commandments” called “Aseret ha-D'vareem” in Hebrew meaning the ten Things or ten utterances. For instance, Jesus says; anyone who even looks at a woman with lust has already committed adultery with her in his heart (Matthew5:28). This is the type of sin that King David pointed out as secret sin….Who can understand his errors? Cleanse thou me from secret faults (Psalm19:12). The internal laws of God are written inside the table of our hearts….

I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people: And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more. (Hebrews8:8-12)

We can only obey God’s eternal laws through the help of the Holy Spirit; without the Holy Spirit, no one can obey the eternal unwritten laws of God which is why each Christian is to be led by the Spirit not by the book (Romans8:14). It’s by the Spirit that one can discern what sin is when it’s not written openly in the scriptures. If you’re practicing a true inner life in Christ, inward purification should be transpiring daily in your heart, following a daily fresh revelation of Christ and inward witness of the Holy Spirit; this is the real meaning of living an inner life, and is what Paul means by working out our salvation with fear and trembling (Philipians2:12). You can evangelize the whole world for God, plant churches and do charity work, but still lose your soul (Mathew7:21-23). Inner life is the path to achieve perfect oneness with the Father (John17:20-24), the nature of sin must be completely erased in us by the living word of God.
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