Rwb, look at verse 31 he is addressing brothers (in Christ)
And then in the next verse inplores them to standfast in the liberty where Christ has made us free
That's why I said Paul is addressing those who believe in Christ, (church) and it is his prayer that they have been born again, or that through his words of warning they might become born again. Without the Holy Spirit coming in us when we are born again, we don't receive fruit that comes from Him. It's not that we have no fruit, but the fruit we do have without the Spirit is natural and without faith (believing unto eternal life). This faith comes through the Spirit sent from Christ, without which it is impossible to please God.
Ga 5:22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness,
faith,
Ga 5:23 Meekness, temperance: against such there is no law.
Ga 5:24 And
they that are Christ's have crucified the flesh with the affections and lusts.
Ga 5:25 If we live in the Spirit, let us also walk in the Spirit.
Hebrews 11:6 (KJV) But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.