It’s ironic to know that Arminian churches (such as Churches of Christ, Methodists, Disciples of Christ, Catholics, Freewill Baptists, etc.) sing gospel songs that were written by those whom they claim are heretics in hell. Talk about straining at a nat and swallowing a camel!! For example, “Rock of Ages” was written by Augustus Toplady, who also wrote:
“Freewill” is an Arminian idol”
“A man’s “freewill” cannot even cure him of a toothache, or of a sore finger, yet he madly thinks it is in its power to cure his soul”
The greatest judgment which God himself can, in the present life, inflict upon a man is to leave him in the hand of his own boasted “freewill”
John Newton the writer of “Amazing Grace” wrote:
“Of all people who engage in controversy, we, who are called Calvinists, are most expressly bound by our own principles to the exercise of gentleness and moderation.”
“This is faith: a renouncing of everything we are apt to call our own and relying wholly upon the blood, righteousness and intercession of Jesus.”
And the list goes on and on, which is no wonder why the gospel songs sung in those churches totally contradict the false, watered-down gospel that’s preached behind their pulpits. For example, “Nothing but the Blood,” “Glory to His Name,” “At the cross,” etc. —-clearly proclaim where the blood of Jesus was applied to His people and it was NOT in water baptism or any other outward ceremony or action! (e.g. Eph.2:13-16). In fact, NONE of the gospel songs EVER insinuate that it is, because it’s not.
Sadly, Arminian churches filter songs such as “Nothing but the Blood” thru the humanistic philosophy that His blood only made people “savable” depending on their “freewill” actions. But if they had ears to hear they’d realize that Jesus Christ is our ONLY plea, not our actions. Again, the song “Amazing Grace,” never insinuates that grace only made it “possible” for a wretch like me to do what it takes to get saved, because that’s not the Bibles version of grace. God’s Word makes it clear that Jesus actually “saves” and He does it to the uttermost, based on His merits, not ours (Heb.7:25, 9:12). He’s not just a hypothetically potential Savior but an actual Savior of actual people that He has chosen.
Arminian churches filter songs such as “Amazing Grace” thru the Roman Catholic idea that grace is “necessary” to do everything it takes to be saved but not sufficient to save in and of itself without our help or cooperation. Naturally when doctrines of devils deceive people into believing their salvation is dependent upon them, they will end up having no “Blessed Assurance” (another song legalists can’t sing in sincerity). Because naturally if one thinks they must do something to be saved, one will also feel they must do something to keep it, rather than believing we are kept by the power of God, thru His irrevocable gift of faith (Rom.11:29, Eph.2:8-10, Phil.1:29, 1Pet.1:5, etc.).
When Jesus is the author and finisher of our faith we can sing gospel songs with a sincere heart, knowing He has granted us a new heart that’s enabled to obey Him out of love and gratitude, rather than legalistic bondage, where sin has dominion. For only God can “make us perfect in every good work to do His will, working in us that which is well-pleasing in His sight, through Jesus Christ; to Whom be glory forever and ever. Amen” (Heb.13:21).
Christ Rescued Me! 
I find it tragic, that in a time Belivers are being squeezed on all sides, uber liberal Protestant Bishops deny fundamental truths in the Word, Catholicism is coming unraveled by its own Pope, beheadings around the world by savage Muslims, and the poor exploited in north and South America by prosperity preachers, that singing Only Believe or Trust and Obey is your big issue. Examine yourself.
In Him, your brother Larry
The big issue is that all false religions have one thing in common, “Freewill” doctrine of man. This is why people are losing faith in God’s word, because if mans will is absolutely free, then the Bible they penned is tainted.
The truth is that God is sovereign and can override man’s will. That’s why we can trust His word. He is powerful enough to keep the message loud and clear——that Jesus Christ is our ONLY hope————-NOT our own fallen will.
If people don’t get this, they won’t get anything else about the gospel.
A false gospel leads to a shipwrecked faith.
“Examine yourself to make sure you’re really in the faith, lest you be a reprobate” 1Cor.3:5