The apostle Paul told the church in 1 Corinthians 3:1: Brothers and sisters, I could not address you as people who live by the Spirit but as people who are still worldly—mere infants in Christ. (NIV)
Many Christians today live similarly to unbelievers because they don’t have the Holy Spirit. That’s why they continue to struggle with sins they were tempted by before coming to Christ.
Galatians 5:16 says:
So I say, walk by the Spirit, and you will not gratify the desires of the flesh. (NIV)
When we have the Holy Spirit we will be convicted of sin and have the power to do what pleases God. That’s why after accepting Christ every believer must be baptized in the Holy Spirit. This is different from water baptism and refers to when the Spirit of God comes to dwell within a Christian (Acts 18:14-17).
You can receive the baptism of the Holy Spirit by praying, fasting, and seeking the Lord. It’s also important to avoid sin because it grieves the Spirit of God (Ephesians 4:30).
The Bible promises that God will give The Holy Spirit to those who ask Him (Luke 11:13)!
Acts 8:15-17 NIV
When they arrived, they prayed for the new believers there that they might receive the Holy Spirit, because the Holy Spirit had not yet come on any of them; they had simply been baptized in the name of the Lord Jesus. Then Peter and John placed their hands on them, and they received the Holy Spirit.