If you read scripture, there should be no uncertainty that you 𝗵𝗮𝘃𝗲 𝗯𝗲𝗲𝗻 saved. When God calls you and you hear the gospel of salvation, and you believe, you are instantly baptized with the Holy Spirit and immersed in the family of God. Scripture is filled with assurances: once you are saved, it's a done deal. You won't ever lose that salvation. So if anyone doubts that, they must not read scripture.
17 So then faith comes by hearing, and hearing by the word of God. (Rom 10)
44 While Peter was still speaking these words, the Holy Spirit fell upon all those who heard the word. 45 And those of the circumcision who believed were astonished, as many as came with Peter, because the gift of the Holy Spirit had been poured out on the Gentiles also. 46 For they heard them speak with tongues and magnify God. (Acts 10)
37 All that the Father gives Me will come to Me, and the one who comes to Me I will by no means cast out. 38 For I have come down from heaven, not to do My own will, but the will of Him who sent Me. 39 This is the will of the Father who sent Me, that of all He has given Me I should lose nothing, but should raise it up at the last day. 40 And this is the will of Him who sent Me, that everyone who sees the Son and believes in Him may have everlasting life; and I will raise him up at the last day.” ( John 6)
3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, 4 just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, 5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, 6 to the praise of the glory of His grace, by which He made us accepted in the Beloved. 7 In Him we have redemption through His blood, the forgiveness of sins, according to the riches of His grace 8 which He made to abound toward us in all wisdom and prudence, 9 having made known to us the mystery of His will, according to His good pleasure which He purposed in Himself, 10 that in the dispensation of the fullness of the times He might gather together in one all things in Christ, both which are in heaven and which are on earth—in Him. 11 In Him also we 𝗵𝗮𝘃𝗲 obtained an inheritance, being predestined according to the purpose of Him who works all things according to the counsel of His will, 12 that we who first trusted in Christ should be to the praise of His glory. 13 In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, 𝘆𝗼𝘂 𝘄𝗲𝗿𝗲 𝘀𝗲𝗮𝗹𝗲𝗱 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝗛𝗼𝗹𝘆 𝗦𝗽𝗶𝗿𝗶𝘁 𝗼𝗳 𝗽𝗿𝗼𝗺𝗶𝘀𝗲, 𝟭𝟰 𝘄𝗵𝗼 𝗶𝘀 𝘁𝗵𝗲 𝗴𝘂𝗮𝗿𝗮𝗻𝘁𝗲𝗲 𝗼𝗳 𝗼𝘂𝗿 𝗶𝗻𝗵𝗲𝗿𝗶𝘁𝗮𝗻𝗰𝗲 until the redemption of the purchased possession, to the praise of His glory. (Eph 1)
8 For by grace you 𝗵𝗮𝘃𝗲 𝗯𝗲𝗲𝗻 saved through faith, and that not of yourselves; it is the gift of God, (Eph
5 For we know that if our earthly house, this tent, is destroyed, we have a building (glorified body) from God, a house not made with hands, eternal in the heavens. 2 For in this we groan, earnestly desiring to be clothed with our habitation (glorified body) which is from heaven, 3 if indeed, having been clothed, we shall not be found naked. 4 For we who are in this tent groan, being burdened, not because we want to be unclothed, but further clothed, that mortality may be swallowed up by life. 5 Now He who has prepared us for this very thing is God, who also has given us the Spirit as a 𝗴𝘂𝗮𝗿𝗮𝗻𝘁𝗲𝗲. 6 So we are always confident, knowing that while we are at home in the body we are absent from the Lord. 7 For we walk by faith, not by sight. 8 We are confident, yes, well pleased rather to be absent from the body and to be present with the Lord. (2 Cor 5)