In Christ you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.
Ephesians 1:13-14 (ESV)
Many wonderful things happened at your new birth in Christ. In Christ, you receive a new identity and nature, as well as a new relationship with your Heavenly Father. You are not judged by what you have done, but rather by what Jesus has done. Furthermore, God gives you the Holy Spirit to seal your salvation through faith until the day of redemption.
According to the Apostle Paul, your sealing by the Spirit is the protection and security of your salvation. You have nothing to fear or worry about losing your salvation. As you learn to live by grace and faith, the Holy Spirit will continually give you the ability to act right and walk in love, empowering you to overcome your sinful habits and the attacks of the devil.
The life of the Spirit flows in and through you, but not everyone lives as if this is true. If you refuse to walk in step with the Spirit, you cannot live freely in Christ. Old sinful habits and thoughts will undermine your faith and cause you to doubt your belief in God. While you are still a child of God, your intimacy and fellowship with Him are affected.
Staying connected to the Holy Spirit allows for greater intimacy with God. Your relationship with God grows deeper and stronger over time because of His rich, generous love. This powerful awareness of God is a life-changing reality where you experience His presence and power in real and tangible ways.