Our eternal life began the moment you believed in the Lord Jesus. In that moment, were born of the Spirit.
Just as Jesus told a man of the Pharisees named Nicodemus, a leader of the Jews:
“Truly, truly, I say to you, unless someone is born [c]again he cannot see the kingdom of God.” and “Truly, truly, I say to you, unless someone is born of water and the Spirit, he cannot enter the kingdom of God. That which has been born of the flesh is flesh, and that which has been born of the Spirit is spirit. John 3:3; John 3:5-6 NASB
Thus, we are born again by the Spirit and we see and enter the kingdom and will never perish.
“As Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in him should not perish, but have eternal life. For God so loved the world, that he gave his only born‡ Son, that whoever believes in him should not perish, but have eternal life. For God didn’t send his Son into the world to judge the world, but that the world should be saved through him. He who believes in him is not judged. He who doesn’t believe has been judged already, because he has not believed in the name of the only born Son of God. This is the judgment, that the light has come into the world, and men loved the darkness rather than the light, for their works were evil. For everyone who does evil hates the light and doesn’t come to the light, lest his works would be exposed. But he who does the truth comes to the light, that his works may be revealed, that they have been done in God.” John 3:14-21 (Jn 3:1-13)
We know that everyone who is born in this natural world will die. Yet, our eternal life in the Spirit continues forever.
Right now, in the Spirit we are seated in Messiah in heaven in the Spirit. (Eph 1:3,20; 3:10; 6:12; Php 2:10; 1Pt 3:22)
Our eternal life is in the Spirit. We are spirit and our spirit will never die. When our natural body dies, our spirit remains in the heaven above as one of the righteous made perfect.
“But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to myriads of [h]angels, to the general assembly and church of the firstborn who are enrolled in heaven, and to God, the Judge of all, and to the spirits of the righteous made perfect, and to Jesus, the mediator of a new covenant, and to the sprinkled blood, which speaks better than the blood of Abel.” Hebrews 12:22-24 NASB
When Messiah Jesus returns to this earth on the last day, we will be changed into our glorified body in which we will see God face to face. (1 Cor 13:12-13)
Only in our glorified body can we withstand God’s glory. It is so radiant that God told His old covenant people, no man can see me and live. Even Moses on Mount Sinai was hid in the cleft of a rock when God passed by him. (Ex 33:18-23)
The Holy Spirit is the seal of our inheritance—the kingdom of God.
“In him/Messiah you also, having heard the word of the truth, the Good News of your salvation—in whom, having also believed, you were sealed with the promised Holy Spirit, who is a pledge of our inheritance, to the redemption of God’s own possession, to the praise of his glory.” Ephesians 1:13-14
The eyes of our hearts are enlightened by the Spirit.
“For this cause I also, having heard of the faith in the Lord Yeshua which is among you and the love which you have toward all the holy ones, don’t cease to give thanks for you, making mention of you in my prayers, that the God of our Lord Yeshua the Messiah, the Father of glory, may give to you a spirit of wisdom and revelation in the knowledge of him, having the eyes of your hearts† enlightened, that you may know what is the hope of his calling, and what are the riches of the glory of his inheritance in the holy ones, and what is the exceeding greatness of his power toward us who believe, according to that working of the strength of his might which he worked in Messiah when he raised him from the dead and made him to sit at his right hand in the heavenly places, far above all rule, authority, power, dominion, and every name that is named, not only in this age, but also in that which is to come. He put all things in subjection under his feet, and gave him to be head over all things for the assembly/church, which is his body, the fullness of him who fills all in all.” Ephesians 1:15-23
We receive our inheritance when the Son of Man comes in his glory.
“But when the Son of Man comes in his glory, and all the holy angels with him, then he will sit on the throne of his glory. Before him all the nations will be gathered, and he will separate them one from another, as a shepherd separates the sheep from the goats. He will set the sheep on his right hand, but the goats on the left. Then the King will tell those on his right hand, ‘Come, blessed of my Father, inherit the Kingdom prepared for you from the foundation of the world; for I was hungry and you gave me food to eat. I was thirsty and you gave me drink. I was a stranger and you took me in. I was naked and you clothed me. I was sick and you visited me. I was in prison and you came to me.’ Matthew 25:31-36
8 Be careful that you don’t let anyone rob you through his philosophy and vain deceit, after the tradition of men, after the elemental spirits of the world, and not after Messiah. 9 For in him all the fullness of the Deity dwells bodily, 10 and in him you are made full, who is the head of all principality and power. 11 In him you were also circumcised with a circumcision not made with hands, in the putting off of the body of the sins of the flesh, in the circumcision of Messiah, 12 having been buried with him in immersion, in which you were also raised with him through faith in the working of God, who raised him from the dead. 13 You were dead through your trespasses and the uncircumcision of your flesh. He made you alive together with him, having forgiven us all our trespasses, 14 wiping out the handwriting in ordinances which was against us. He has taken it out of the way, nailing it to the cross. 15 Having stripped the principalities and the powers, he made a show of them openly, triumphing over them in it. Colossians 2:8-15
1 If then you were raised together with Messiah, seek the things that are above, where Messiah is, seated on the right hand of God. 2 Set your mind on the things that are above, not on the things that are on the earth. 3 For you died, and your life is hidden with Messiah in God. 4 When Messiah, our life, is revealed, then you will also be revealed with him in glory. Colossians 3:1-4
Unless noted, all Scripture quoted above is from the World Messianic Bible.