Earlier this month I went to The Cove in Asheville, N.C., to be blessed by the teaching ministry of Dr. John MacArthur. I had never seen Dr. MacArthur "live" until then. But on April 15, 2008, I saw him "in the flesh." I also saw several hundred other Christians there in the flesh. We were indeed blessed by Dr. MacArthur's lessons that day delivered while he and the rest of us were there "in the flesh." However, his message and our hearing were experienced "in the spirit," our in-the-flesh bodies interfering only when we had had too much coffee or were temporarily distracted by someone coming or going.
We are Christ's sheep and we heard the Good Shepherd's voice, His word, through His servant, Dr. MacArthur. We are His sheep in mortal bodies. In these flesh and blood bodies we are enabled to hear His voice and recognize it by the new life we have due to the presence of the Holy Spirit within; we have "ears to hear" (I Cor. 2:9-16, the "mind of Christ"). And Jesus assured us that, "My sheep hear My voice, and I know them, and they follow Me" (Jn. 10:27). This is the experience of in-the-flesh Christians, the only kind there are.
This present in-the-flesh life with all its trials, sins, and flaws belongs to our Lord and Savior, bought with His "precious blood" (I Cor.6:19; Acts 20:25-28; I Pet. 1:17-21). Therefore when the Word of God in the NT epistles refers to believers as being in the flesh, it differentiates between us and the ungenerate who are "in the flesh." We have problems that arise directly from our yet being in the flesh (Rom. 8:13, 18-21). But, we have faith in the Lord Jesus. We are the in-the-flesh elect of God who by His grace alone, through faith in Christ alone, have been justified by God through our faith. Our faith (the "gift of God") not only saves us but makes this in-the-flesh existence bearable and even victorious and joyful (Rom. 8:28-39; I Jn. 5:4-5; 1:4).
So then, the "flesh" of Gal. 2:20 is the flesh of one who has been crucified with Christ, not the "flesh" of Rom. 8:9. The flesh is still flesh for the believer. But it is the flesh of the justified; it is the flesh of grace. We still sin. But by God's gracious election through the promise, our sins are forgiven. We are redeemed, justified, sanctified and reconciled through "the body" of His dear Son. He did in His flesh and blood body what no man could do and His merit is written down on our account (Rom. 8:1-4; 4:22-25). This life which I now live in the flesh I live by faith in Him.