John 6: 28 Then said they unto him, What shall we do, that we might work the works of God?
29 Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.
Our ability to believe at all is the work of God! Our complete salvation is His work, including the saving faith we possess, our very faith is His work alone! To wit:
John 6:44 No one can come to me unless the Father who sent me draws them, and I will raise them up at the last day.
Romans 8:30 And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
1 Cor 12:3b ...and no one can say, "Jesus is Lord," except by the Holy Spirit.
Philippians 1:6 being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus.
Salvation is initiated, caused to be believed upon and completed by God alone!!
Wesley preached Whitfield's funeral and toward the end these words:
3. That both these accounts are just and impartial, will readily be allowed; that is, as far as they go. But they go little farther than the outside of his character. They show you the preacher, but not the man, the Christian, the saint of God. May I be permitted to add a little on this head, from a personal knowledge of near forty years? Indeed, I am thoroughly sensible how difficult it is to speak on so delicate a subject; what prudence is required to avoid both extremes, to say neither too little nor too much! Nay, I know it is impossible to speak at all, to say either less or more, without incurring from some the former, from others the latter censure. Some will seriously think that too little is said; and others, that it is too much. But without attending to this, I will speak just what I know, before Him to whom we are all to give an account.4. Mention has already been made of his unparalleled zeal, his indefatigable activity, his tender-heartedness to the afflicted, and charitableness toward the poor. But should we not likewise mention his deep gratitude to all whom God had used as instruments of good to him? -- of whom he did not cease to speak in the most respectful manner, even to his dying day. Should we not mention, that he had a heart susceptible of the most generous and the most tender friendship? I have frequently thought that this, of all others, was the distinguishing part of his character. How few have we known of so kind a temper, of such large and flowing affections! Was it not principally by this, that the hearts of others were so strangely drawn and knit to him? Can anything but love beget love? This shone in his very countenance, and continually breathed in all his words, whether in public or private. Was it not this, which, quick and penetrating as lightning, flew from heart to heart? which gave that life to his sermons, his conversations, his letters? Ye are witnesses!
Wesley points out that their intent always had been to emphasize that all was of God, that they were preaching salvation and justification, and not just the utter sinfulness of man, but that he was dead in his trespasses and sins.
In sum, it was God's grace to which both were trying to be true.
It's the same in our day. Some brothers and sisters in Christ are standing up for God's grace the best they know how, and that is a biblical stand. Because it's biblical, they run across passages that lead to seemingly contradictory conclusions, that salvation is open to all and that salvation is limited to those selected by God.
The passages that have always been my starting point are: Ro 8:29 "those He foreknew He predestined" and Acts 16:14 "One of those listening was a woman named Lydia, a dealer in purple cloth from the city of Thyatira, who was a worshiper of God. The Lord opened her heart to respond to Paul's message."
From our perspective in time, God knows those who are to become His sheep, and even in their lives He works with them, even to the opening of their hearts to hear the gospel.
From God's perspective over time, God has always known His sheep.