Men by nature are unwilling and at enmity against God, will not and cant submit to God. So if a person becomes willing, then that's indicative God has changed them, saved them and given them a new heart.
Rom 8:7
7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
warning for believers
1 Corinthians 10:1-15
New International Version
Warnings From Israel’s History
10 For I do not want you to be ignorant of the fact, brothers and sisters, that our ancestors were all under the cloud and that they all passed through the sea. 2 They were all baptized into Moses in the cloud and in the sea. 3 They all ate the same spiritual food 4 and drank the same spiritual drink; for they drank from the spiritual rock that accompanied them, and that rock was Christ. 5 Nevertheless, God was not pleased with most of them; their bodies were scattered in the wilderness.
6 Now these things occurred as examples to keep us from setting our hearts on evil things as they did. 7 Do not be idolaters, as some of them were; as it is written: “The people sat down to eat and drink and got up to indulge in revelry.”[
a] 8 We should not commit sexual immorality, as some of them did—and in one day twenty-three thousand of them died. 9 We should not test Christ,[
b] as some of them did—and were killed by snakes. 10 And do not grumble, as some of them did—and were killed by the destroying angel.
11 These things happened to them as examples and were written down as warnings for us, on whom the culmination of the ages has come. 12 So, if you think you are standing firm, be careful that you don’t fall! 13 No temptation[
c] has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted[
d] beyond what you can bear. But when you are tempted,[
e] he will also provide a way out so that you can endure it.
Idol Feasts and the Lord’s Supper
14 Therefore, my dear friends, flee from idolatry. 15 I speak to sensible people; judge for yourselves what I say.