"Do you believe you have to be approved by GOD for salvation or is it a free gift?"
I believe God give the gift of salvation to those who He will. This has been my experience. This is what the early church taught. And this is what the scriptures says.
Since our salvation IS a gift, like a Christmas present, God is not going to rescind it and He has sealed his Holy Spirit inside us which is our guarantee to the praise of His glory. The last part of the "Study to show yourself approve.." states "...so you will NOT be ashamed." I think it would be tragic to get before the throne of our Lord Jesus and be ashamed for not following the scripture that God has given us.
Please keep in mind our shepherd fights our battles. Not us. If we try to do so it becomes a struggle. But we serve an all powerful God who cares for us and will fight for us but He rightfully wants and deserves the recognition and the glory.
2Ch 20:17 'You need not fight in this battle; station yourselves, stand and see the salvation of the LORD on your behalf, O Judah and Jerusalem.' Do not fear or be dismayed; tomorrow go out to face them, for the LORD is with you."
Rather than becoming so concerned as to whether or not an experience is from God or not, it might be more appropriate to recognize we, as believers, when we are in fellowship with Him, are alive in the spirit.
Just as we might identify with physical conflict and intellectual debates, there is also a very real warfare in the spiritual domain.
I suspect too many of us behave like sheep,..stupidly blundering about out of habit, just not catching on to what he has provided for us in a very calm, clearly level-headed fashion, from love and patient perseverence.
Many become obsessed with the spectacular, when the most significant features in warfare might have no spectacular significance.
Salvation might be associated with an experience for some people, while for others the moment of salvation is purely a thought exercise of simple faith in Him.