score:1
"How do you know it was God at work? How do you know that person didn't make those changes on his/her own will?"
From a synergistic perspective , the short answer is both. God is always working. We can choose to work with Him, in which case it is still Him working through us. We can choose to work against Him, but choosing that path inevitably leads to discipline and correction, which may be unpleasant but ultimately is a good work of God. In any of these cases it is valid to say "God is working" because the outcome is ultimately good, and...
Every good gift and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change. (James 1:17 ESV)
Even when we are cooperating with God, we still attribute the goodness to His will rather than our own to avoid any appearance of pride or boastfulness.
If you belong to a monergistic tradition then the above doesn't apply, it is only God who is ever at work.
In the case of an unbeliever, this probably doesn't make any sense at all since they only recognize the will of the person is in play.
Upvote:0
God is always at work - but it is interesting to point out that so is the enemy.
The evidential result here is someone turning their back to evil and trying to align themselves with God. In that way, they we can describe their interactions and intentions as "God is at work" from the relative perspective of the person. It is more like who are you following and what are the results "work" your life shows?
You will hear the phrase in question more in the evangelical and born again churches rather than the traditional. If someone has been a drug addict their whole life and has a religious "experience" or epiphany - it definitely (at least) feels like God is at work, regardless of doctrine.
Upvote:3
Early Christians were often exhorted to "test every Spirit" to see if it was of God. (1 John 4:1).
When the Bible was first received, there was very little question of whether or not spirits were at work, but rather which ones. For this reason, the question "Is it God" isn't particularly within the domain of Scripture - or even doctrine. God is assumed to be ultimately responsible for it all, so of course, it is "of God."
As to the question of whether or not a person is saved, there is also a simple test. As Matthew records Jesus' Sermon on the Mount, the key idea is "by their fruits you will know them."
“Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves. 16By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? 17Likewise every good tree bears good fruit, but a bad tree bears bad fruit. 18A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. 19Every tree that does not bear good fruit is cut down and thrown into the fire. 20Thus, by their fruit you will recognize them.
21“Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. 22Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?’ 23Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers!’