8:5 Those who live according to the flesh have their minds set on what the flesh desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires.
8:6 To set the mind on the flesh is death, but to set the mind on the Spirit is life and peace.
8:7 For this reason the mind that is set on the flesh is hostile to God; it does not submit to God’s law– indeed it cannot,
8:8 and those who are in the flesh cannot please God.
8:9 But you are not in the flesh; you are in the Spirit, since the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.
8:10 But if Christ is in you, though the body is dead because of sin, the Spirit is life because of righteousness.
8:11 If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ from the dead will give life to your mortal bodies also through his Spirit that dwells in you.
In the deeper points of Christian salvation the Bible reveals that when we become Christians we are made new creatures in Christ. This is done by the process described in Romans. Our flesh which is dead because of sin is reanimated by the Holy Spirit who is alive in us. This is also one reason why many Christians hold to the once-saved, always-saved salvation theology. Whether or not one believes in such pieces of theology, one thing is clear, that we still have to decide if we are going to walk in the flesh or the Spirit. Romans 8:5-6 is an exhortation to the Christians in Rome to choose to walk in the Spirit and not the flesh, for the flesh is not in accordance with the Spirit.
Every day for those who follow Christ is a day that one must chose to walk in the Spirit. Every day when I go into work, I have to choose to walk in accordance with the instructions of Jesus and the leading of the Spirit, for my flesh would likely do otherwise. My human flesh is not always in accordance with the Lord, which is why I must follow the leading of the Holy Spirit. We must all heed the leading of the Spirit.