Since motivationalism moves those who are “alienated and hostile towards God” (Col. 1:22), what does that say about those whom He “has saved… and called… with a holy calling not according to [their] works, but according to His purpose and grace which was given to [them] in Christ Jesus before the beginning of time” (2 Tim 1:9)? Does God save people that don’t work for Him? Better, is a saved person not going to work for God? No. Matt Papa sings, “If you love Him (Christ) you would keep His Word…” Submission to the Gospel requires action, “if indeed you remain steadfast and grounded in the faith and are not shifted away from that hope of the gospel that you heard” (Col. 1:23). Can a nonbeliever work for God? No. They might act as a Christ follower; however, their actions glorify themselves or others and not God. The chief end of man, according to the shorter catechism, is “to glorify God and enjoy Him forever”. The lack of direction of glory is due to the lack of justification and future glorification.
Can someone who has not submitted their life to the gospel share the gospel to someone who becomes regenerate? This question looms over me. My immediate response is no; however, who saves? Christ. By what means? The Gospel. As mention before in Romans 1:16 the Gospel is God’s power of salvation; therefore, I am convinced if an unregenerate shares the gospel to another Christ can accept that person despite the medium. God saves, not man. Mankind does not need a mere human* high priest (Christ is our only high priest, Hebrews 7); however, mankind needs a middle man for specific revelation (not necessarily human, the scriptures are sufficient).
Several red flags to fly up at the idea of an unsaved person sharing the gospel: he hasn’t fully submitted his life to it. Thereby, his sharing of the gospel can easily be devoid, baseless, and incomplete. Motivationalism sends a meaningless gospel to the world. Praise the LORD’s sovereignty since the Spirit can work despite the motivationalized gospel.
The elect are commanded the Great Commission. John Piper says bluntly, “go, send or disobey.” If the faithful were no longer few, perhaps the motivationalized gospel could be stopped. If one is saved and does not share the gospel, he should question his salvation. Not that he is necessarily unsaved, but he is definitely disobedient. If one is sharing the gospel and unsure of his salvation, he should question his motives.
* I do understand the hypostatic union of Christ’s humanity and divinity, which is why I chose the word “mere” as in someone who is human alone.