“The one who comes to Me I will by no means cast out” (John 6:37)

Christ didn’t put a limit on His promise. He didn’t say, "I won’t cast out a believer the first time he comes”. The original Greek can mean either “in no manner” or “at no time” will Christ cast out.

Saints can always come to Christ. “If anyone sins, we have an Advocate with the Father, Jesus Christ the righteous” (1 John 2:1). But what if a saint backslides? “I will heal their backsliding, I will love them freely, For My anger has turned away from him” (Hosea 14:4). But what if a saint is tempted to gross sin? “No temptation has overtaken you except such as is common to man; but God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will also make the way of escape, that you may be able to bear it” (1 Corinthians 10:13).

But what if a saint commits adultery and murder, the sins of King David? Yes, God will
purge him with hyssop, and he shall be clean; wash him, and he shall be whiter than snow, and blot out all his iniquities (Psalms 51:7-9).

Christ promised, “I give them eternal life, and they shall never perish; neither shall anyone snatch them out of My hand” (John 10:28). Christ won’t love you for a while and then give up on you. If God chose you before the foundation of the world, and predestined you to adoption as His son (Ephesians 1:4-5), you will be presented to Christ without spot or wrinkle (Ephesians 5:27).

When you stumble, quickly repent and come to Christ. Trust His promise to saints, “I will by no means cast out”

"Once in Christ, in Christ for ever, Nothing from His love can sever."