It is common for our evangelical friends to use biblical passages like Ephesians 1:12-14 and John 10:27-30 as prooftexts to prop up the idea that we can never fall from a saved condition. This is commonly referred to as a "once saved/always saved" perspective. Theologians call it the doctrine of "perseverance" or "eternal security."
Ephesians 1 says that true believers are "sealed with the Holy Spirit of promise" and that it is "the earnest of our inheritance." John 10 says, "I give them eternal life, and they shall never perish; no one can snatch them out of my hand."
The above two passages contain marvelous promises and are absolutely true, but we cannot simply isolate scriptures that we want and ignore the rest. Scripture interprets scripture, and these promises must be understood in light of the entire context of the Bible. Following are just two of several verses applying to this subject that many Evangelicals are reluctant to discuss:
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, and have tasted the good word of God, and the powers of the world to come, if they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
For if they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them. But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
II Peter 2:20-22
So what is the meaning of the above four passages? Ephesians 1 tells us that when we surrender to Christ as Lord, we are marked with the seal of His Holy Spirit, an evidence of the promise of eternal life.
John 10 gives believers a marvelous promise of eternal life saying, "no one can snatch them out of my hand." In other words, no other human being can determine your eternal destiny. Once God has granted you eternal life, it is only by exercising your free will to reject the gospel that you could be lost. Each person will be judged according to their own individual response to Christ's gospel.
Hebrews 6 makes it clear that people have the agency to choose. Unfortunately, even after they have been "partakers of the Holy Ghost," it is possible for them to "fall away" and reject the gospel. II Peter warns us that those who have had the "knowledge of the Lord and Savior Jesus Christ" can be "overcome." Peter goes on to say, "the latter end is worse with them than the beginning."
But he that received the seed into stony places, the same is he that heareth the word, and anon with joy receiveth it; yet hath he not root in himself, but dureth for a while: for when tribulation or persecution ariseth because of the word, by and by he is offended. He also that received seed among the thorns is he that heareth the word; and the care of this world, and he becometh unfruitful.
On at least two occasions, Jesus, our Lord, promised eternal life to those who endure to the end:
..... but he that endureth to the end shall be saved.
But he that shall endure to the end, the same shall be saved.
Once you have found that pearl of great price, that precious gospel, Jesus calls you to "endure to the end" and to "work out your own salvation with fear and trembling" (Philippians 2:12).
You may ask, "How do you have an assurance of salvation if you believe one can fall from grace?" I have absolute assurance by the power of God's Holy Spirit and His promises implicit in scripture that if I died today, He would accept me into His kingdom. There is no doubt in my mind. I would have to openly reject Christ's gospel in order to jeopardize my salvation in any way. I have not done that. I trust in the promises of Christ, my Savior and Lord.
In light of passages like Hebrews 6 and II Peter 2, are you concerned about evangelical churches that offer false guarantees of salvation? The idea of enduring to the end is a vital element of Christ's gospel. Please do not be deceived by a gospel of "acceptance." Once you have found that precious gospel, you must faithfully endure to the end.