I claim to affirm the following. The first is from Luke’s Gospel:

And when his disciples asked him what this parable meant, he said, “To you it has been given to know the secrets of the kingdom of God, but for others they are in parables, so that ‘seeing they may not see, and hearing they may not understand.’ Now the parable is this: The seed is the word of God. The ones along the path are those who have heard; then the devil comes and takes away the word from their hearts, so that they may not believe and be saved. And the ones on the rock are those who, when they hear the word, receive it with joy. But these have no root; they believe for a while, and in time of testing fall away. And as for what fell among the thorns, they are those who hear, but as they go on their way they are choked by the cares and riches and pleasures of life, and their fruit does not mature. As for that in the good soil, they are those who, hearing the word, hold it fast in an honest and good heart, and bear fruit with patience.

The second is from the Westminster Confession of Faith, chapter 10, paragraph 4:

Others, not elected, although they may be called by the ministry of the Word, and may have some common operations of the Spirit, yet they never truly come unto Christ, and therefore cannot be saved

So, are both these things true? I think so.

Or is anyone who claims that people believe for a while and then fall away guilty of violating the Westminster Standards?

If I am wrong and one is violating the Westminster Standards by affirming that apostates (or some of them) “believe for a while,” would that be preferable to contradicting Jesus?