The reason that you cannot be led by the Holy Spirit is because you don't have the Spirit. The religious unsaved are led by laws and rules, just like the Pharisees. Christians are not led by law, they are Spirit led.
The law is Spiritual.
Romans 7:14 We know that the law is spiritual; but I am unspiritual, sold as a slave to sin.
You say Paul is not a Christian.
1 Corinthians 9:21 To those not having the law I became like one not having the law (though I am not free from God's law but am under Christ's law), so as to win those not having the law.
Romans 2:14
Indeed, when Gentiles, who do not have the Law, do by nature what the Law requires, they are a law to themselves, even though they do not have the Law,
What does this mean?
Romans 2:12
All who sin apart from the Law will also perish apart from the Law, and all who sin under the Law will be judged by the Law.
What did Paul mean by this:
Galatians 6:2
Carry one another's burdens, and in this way you will fulfill the Law of Christ.