WIth all the threads on OSAS and eternal security, I don't expect there would be anything new on this thread.
The Biblical answer to the question posed by this thread is simply…"no".
All references are from the NASB:
First, Paul described both justification (Rom 3:24, 5:15,16,17) and eternal life (Rom 6:23) as gifts of God. Then he wrote Rom 11:29 - the gifts and calling of God are irrevocable. Since he had already described what he meant by "gifts of God", there was no reason for him to specifically list what he meant by "gifts of God".
3:24 - being justified as a gift by His grace through the redemption which is in Christ Jesus
6:23 - For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
11:29 - for the gifts and the calling of God are irrevocable.
Second, every believer is sealed with the Holy Spirit when they believe (Eph 1:13). This sealing is a pledge with a view to the redemption of God's own possession (believers - Eph 1:14).
And, this sealing is for the day of redemption (Eph 4:30).
1:13 - In Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise
1:14 - who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory.
4:30 - Do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
Third, Jesus tells us WHEN one HAS eternal life; when they believe (Jn 5:24). Then, He tells us that those to whom He gives eternal life WILL NEVER PERISH (Jn 10:28).
5:24 - “Truly, truly, I say to you, he who hears My word, and believes Him who sent Me, has eternal life, and does not come into judgment, but has passed out of death into life.
10:28 - and I give eternal life to them, and they will never perish; and no one will snatch them out of My hand.
Fourth, Paul stated that regardless of the believer's lifestyle, or "whether we are asleep or awake, we will be together with Him" in 1 Thess 5:10. The context begins in v.4 and contrasts believers with unbelievers, or day with night, or being alert with being asleep or sober with drunkeness.
4 But you, brethren, are not in darkness, that the day would overtake you like a thief;
5 for you are all sons of light and sons of day. We are not of night nor of darkness;
6 so then let us not sleep as others do, but let us be alert and sober.
7 For those who sleep do their sleeping at night, and those who get drunk get drunk at night.
8 But since we are of the day, let us be sober, having put on the breastplate of faith and love, and as a helmet, the hope of salvation.
9 For God has not destined us for wrath, but for obtaining salvation through our Lord Jesus Christ,
10 who died for us, so that whether we are awake or asleep, we will live together with Him.
Analysis of this passage:
v.4 tells us that believers are "not in darkness"
v.5 differentiates believers (sons of light and day) with unbelievers (not of night or darkness).
v.6 encourages believers to not live like unbelievers (not sleep as others do, but be alert and sober).
v.7 describes unbelievers and what they do.
v.8 explains that "since we are of the day" (believers), we need to be sober.
v.9 explains the destiny of the believer - not destined for wrath but for salvation
v.10 says that regardless of the believer's lifestyle, we will live together with Him.
Fifth, there are absolutely zero verses that warn us plainly that one can lose their salvation.
Those who believe that salvation can be lost have quite clearly rejected these 15 verses which teach that salvation cannot be lost.