Satan has a relationship with Jesus; albeit, a hate and war-filled one, but nonetheless, as messed up as it is, they have a relationship. The demons believe in Jesus and even tremble before Him, but in the end they're still going to be thrown into the lake of fire for all eternity. I've engaged in many discussions where the person says, "I have a relationship with Jesus," but his or her lifestyle proves otherwise (ref. Matthew 7:15-20, Galatians 5).
Having a relationship with Jesus and/or believing in Him does not mean you are going to heaven. There is a spiritual identification badge of sorts that a person must have if he or she desires to enter heaven. Thankfully, Jesus tells us exactly what that identifier is in John 3:3-8. “Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.” Nicodemus said to Him, “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” Jesus answered, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’ The wind blows where it wishes, and you hear the sound of it, but cannot tell where it comes from and where it goes. So is everyone who is born of the Spirit.”
In order to walk through those pearly gates, we must be born again. "Born again" is not a sect of Christianity. The devil has done a nice job deceiving many into believing it is, but it absolutely is not a denomination. When Christians ask, "Have you been born again," what we're really asking is, "Have you repented of your sins and trusted in Christ as Lord and Savior and been made alive and transformed by His Holy Spirit?"
If you aren't sure if you've been born again, chances are it's because you haven't. You may have a religion, or some form of religious association or ritual, but you have not been sealed by the Holy Spirit (ref. Ephesians 4:30).
So now there is no condemnation for those who belong to Christ Jesus. And because you belong to Him, the power of the life-giving Spirit has freed you from the power of sin that leads to death (Romans 8:1-2 NLT).
If we don't have the Holy Spirit, we have not been made free from sin, and sin leads to death.
The law of Moses was unable to save us because of the weakness of our sinful nature. So God did what the law could not do. He sent His Own Son in a body like the bodies we sinners have. And in that body God declared an end to sin’s control over us by giving His Son as a sacrifice for our sins. He did this so that the just requirement of the law would be fully satisfied for us, who no longer follow our sinful nature but instead follow the Spirit of God.
Those who are dominated by the sinful nature think about sinful things, but those who are controlled by the Holy Spirit think about things that please the Spirit. So letting your sinful nature control your mind leads to death. But letting the Holy Spirit control your mind leads to life and peace. For the sinful nature is always hostile to God. It never did obey God’s laws, and it never will. That’s why those who are still under the control of their sinful nature can never please God.
But you are not controlled by your sinful nature. You are controlled by the Spirit if you have the Spirit of God living in you. (And remember that those who do not have the Spirit of Christ living in them do not belong to Him at all.) And Christ lives within you, so even though your body will die because of sin, the Spirit gives you life because you have been made right with God. The Spirit of God, who raised Jesus from the dead, lives in you. And just as God raised Christ Jesus from the dead, He will give life to your mortal bodies by this same Spirit living within you. (ref. Romans 8:3-11)
If you have the Holy Spirit living inside of you, you will be resurrected at the Last Day when Christ says goodbye to this earth and unveils the new, eternal city He made for His children.
But there's an extremely dangerous false teaching that has infiltrated the Church and is growing evermore popular, especially in hipster churches. The doctrine is if you just say a prayer, or begin a relationship with Jesus, you're going to heaven. The vital information about needing to be born again by the Holy Spirit is often missing nowadays at the pulpit and in evangelism period. But we cannot afford to miss this, beloved. If we do not teach what Jesus said about how to get to heaven, our gospel presentation is weak at best, or deceptive and destructive at worst.
We will know a soul has been born again by the fruit his or her life bears. How many who attend church-service weekly, or even serve, think they're saved from hell, even though they're following their sinful nature, displeasing God, and thus walking the path of death?
Let's be alert and faithful. Let's bring the world the true gospel and make real disciples before everyone's time is up and Judgement Day is upon us all.
God's power and love be multiplied to you as you seek to please Him.