I was recently at a church and the pastor told me that we as born again believers in Christ can lose our salvation if we are saved but then decide to "reject the Holy Spirit" and also if we are walking with our Savior Jesus but then sin, and then die while sinning, he says that we can be lost for eternity and we would be rejected by Jesus on judgement day. What's up with that?
There are only two ways you can lose your salvation:
#1) If you willingly put yourself back under a yoke of bondage, assuming you must "do" something in order to be saved. We are saved by grace, through faith. If we hold strong to that faith, fully persuaded the only thing that could cover our sins is the blood sacrifice Jesus gave at the cross, we will never have any condemnation, but we will have eternal life.
Read Galatians. Many Christians start out by faith, and they are saved because they trust God and what His Son did. But Satan tries to bring in destructive ideas that we need to "do" something to make sure we're saved. The only thing we "do" is believe in Jesus' work on the cross. What happens to people is they "fall away" from the glorious grace which is continually being given out to Christians as they walk with the Lord and stumble as they mature.
Now there are many stern warnings against wantonly sinning even though we have this faith, and I will explain about why that is important at the end.
#2) The second way we can lose our salvation is if we deny Jesus is Lord, King, and our Savior. When we do this, we basically reject what He did on the cross and we invoke the curse of the law onto ourselves. This is why it's important for people to be "clothed with power from on high" with the Holy Spirit of God. Have you been baptized with the Spirit of God? Start praying for that baptism if you have not.
Peter denied Jesus three times! Peter was saved, Jesus breathed His Spirit onto Him in John chapter 20. He was spiritually made alive. But that was before the day of Pentecost, wherein he was dipped into the power of the Holy Spirit and given power to overcome sin, this world, and the evil one. They are two different things. Being saved by faith is the first step. The baptism of the Holy Spirit for power from on high is something that is available to those who are saved by faith. This power will get you through any trial or tribulation. Additionally, God is so merciful that if He puts you into a position where you have to chose, I believe He will give you the strength to stand strong in Christ. Every day, all across our world, people are martyred for Jesus. They do not deny Him, and He does not deny them.
Now about all the warnings about sin: Sin is deceitful. The LORD personified sin when He spoke of it in scriptures because it's powerful in our bodies and it will continually try to drag us away from the Lord if we're not careful.
This means Christians should not take sin in their lives lightly. If we do, we risk becoming deceived by our sin and ending up where we will either fall away from grace and accept a yoke of bondage as I mentioned in the first instance, or we will become weak enough in our faith that we will deny our Lord.
If you are conscious of your sin, and you know it's bad, and you're continuing on with the Lord, you have nothing to fear. There is no condemnation for those who are in Christ! Confess your sin daily, and He will cleanse you.
Consider when Jesus washed the apostles feet. Peter said he wouldn't let Him. Jesus said, "If I don't cleanse you, you have no part in Me."
Jesus was talking of the importance of spending time with Him, abiding in Him, so He can sanctify us as we walk in this world. Our feet will get a bit dirty, we will stumble and make mistakes and sin still. But He will clean us up and keep us holy.
Then Peter was like, "Wash my head and everywhere then!"
Jesus said, "The one who has bathed does not need to wash, except for his feet, but is completely clean. And you are clean..."
This scripture says so much! Check it out: If you have faith that Jesus covered your sins with His saving work at the cross, you are "bathed." That means you have been clothed with His righteousness and are now able to boldly go to God's throne as one of His children. You don't need to take a bath, you just need to spend time with Him so He can wash the dirt from our feet as we walk in this world in these fragile, fallen vessels.
My friend, do not be afraid. Stand strong in what Jesus did for us! There's nothing else in the world that can save us. Then, spend time with Him every day. Confess your sins to Him every day, and be fully persuaded that when you do so Jesus is washing your feet. By faith, you will know you have been cleansed and that no guilt remains. You are free from condemnation!