Then Jesus said to the twelve, "Do you also want to go away?" But Simon Peter answered Him, "Lord, to whom shall we go? You have the words of eternal life. John 6:67-68
Speaking of the level of commitment to Christ required of those who trust in Him for salvation, Jesus spoke figuratively of the need for believers to eat His flesh and drink His blood (v.53 & 63). Many misunderstood and stopped following Him (v.66).
Turning to the twelve, Jesus asked if they too wanted to go away as well (v.67). Peter wisely acknowledged that they could not forsake Him, because Jesus possessed, and therefore spoke, the words of eternal life (v.68).
When a person understands that following Jesus, and never turning away from Him, is the only way to inherit eternal life—where else could we possibly go?. When we hear and understand the gospel, trust in, and follow Jesus—where else could we possibly go?
Those who understand this are virtually assured to experience temptations, and trials, and even persecution. As difficult as these may be, and as often as we may temporarily stumble, those who are born again by the Holy Spirit of God will never ultimately forsake the Lord!