If they come to believe Jesus then they will no longer be muslims.. So they cannot be messianic muslims..
They can be Messianic Muslims in the same way that Paul could be a Messianic Jew and you can be a Messianic
whatever your pre-Christian heritage or culture is. (Mine going way back was Celtic polytheism, but more recently it was combined with Protestantism of the Baptist variety.) As Christians we are Spiritual Jews.
The 44th TOJ is that GRFS may be stated as "
Ask/seek/knock (MT 7:7-11/LK 11:9-13); ask what is true, seek salvation, and knock on heaven’s door (cf. HB 11:6).
The parallel passage in Luke says the Holy Spirit will be given to those who ask. Thus,
sincerely seeking salvation is regarded by God as righteousness (cf. RM 4:3), probably because God knows that were a seeker given the opportunity to hear the Gospel, he/she would believe and be saved or sanctified {JN 17:17}. A soul enters the path of salvation at the moment he/she decides to ask/seek/knock, but all primitive paths eventually converge onto the highway to heaven at the point of accepting Christ (TOJ #49). James 1:5&17 teaches this truth in terms of wisdom. Its converse is that those who are not truth-seekers will not LGW/satisfy GRFS. {MT 21:24-27//MK11:29-33//LK 20:3-8, MT 22:18//MK 12:15//LK 20:23-24}
The reason that GRFS may be stated in terms of seeking what is true, is because
a logical train of thought leads an unbiased truthseeker to have a propensity to believe in an all-loving God, who is not tricky and does not hide the way to heaven (HB 11:6, ACTS 13:10). The Bible says God’s Spirit is love and truth (1JN 4:8 & 5:6), which means all love (agape, RM 6:5-8) in all people is God’s operation, and all truth in all cultures is God’s revelation. Thus,
becoming a Christian theist does not mean rejecting what is good or loving and true in one’s pre-Christian experience or culture. Again, all truth is from God and manifests God’s Spirit, so if any atheists are truthseekers, then they are not far from the kingdom of God (MK 12:34, 2THS 2:10, JN 18:37) because Jesus promised that those who seek will find (LK 11:9&13).
A person’s fellowship with God begins in a primitive and impersonal way when a soul becomes a truthseeker, because God’s Spirit is truth (1JN 5:6). The commitment to seek and have faith in the truth as revealed is a primitive “pre-theistic” satisfaction of GRFS (MT 7:7), thus the person begins a saving relationship with God although he/she does not know it (RM 1:17). As a truthseeker at any time in history and place in the world meditates upon his/her experiences, Paul indicates that they will be able to discern God’s being and love (RM 1:20, 2:14-15, GL 5:14) by means of what theologians call “natural or general revelation”. This stage occurred from Adam to Moses per RM 5:12-14.
Three ways God/Christ is encountered or found include: 1. general revelation, which includes meditating on the natural world or God’s supernatural work. Paul says men are without excuse, both because God’s eternal power and divine nature (love) are manifested by creation (RM 1:20), and because a proto-gospel has been proclaimed to everyone under heaven implicitly or in pre-NT foreshadowings (CL 1:23, RM 10:13-18, GL 3:8). 2. the inner conscience, a natural or “common” sense (RM 2:14-16), which manifests morality or a moral Authority in every culture; and 3. special revelation (1PT 1:8-12), which refers to the biblical and especially NT teaching regarding God’s history of salvation. Again, the Parable of the Talents indicates that souls are saved via faith in God/ Christ as revealed (cf. 1CR 10:1-5). Truthseekers around the world in all times are pilgrims at various places along the road of life, and all true roads eventually lead to the Way to eternal life in heaven (JN 14:6, ACTS 24:14, PHP 2:10-11). All truth leads to One Way.
The mind of Jesus is truth incarnate (JN 1:14), and all truth manifests the Spirit of Christ or God (1JN 5:6).
The work of God (GRFS) is to seek and believe the truth, and part of the truth is that no one comes to know God as Father except through faith in God’s truth embodied as God the Son. If a moralist truthseeker (on the basis of general revelation) is taught about God (perhaps via the OT or Qur’an), then he/she may choose to believe in God or become a theist. If theists are taught the Gospel (NT), then they may choose to believe/accept Jesus as Christ. In both cases salvation is a gift from God received by faith “from first to last” (RM 1:17).
When truthseekers recognize the reality of God as the Creator of the universe who has a moral requirement, if they decide to become theists and worship Him, they become like Abraham and other OT believers, and their fellowship deepens or becomes personal. RM 4:1-25 teaches that Abraham believed God and it was credited to him as righteousness (v.3). Then this spiritual event was signified outwardly by circumcision (v.11). Similarly, all who believe in God are credited to be righteous and spiritual children of Abraham, although physical circumcision is optional (v.11-18).
RM 5:6-11 says that while we were powerless (unable to save ourselves via works per 3:9-20),
Christ died for the ungodly or sinners or God’s enemies, so that believers (3:22-26) are justified or reconciled and saved from God’s wrath. This includes
all of humanity potentially, comparable to how humanity became sinners following the original trespass (5:15-21). Presumably, God provides pre-Christian believers the opportunity to hear the gospel of Christ in a pre-NT and pre-Abrahamic or provisional form (cf. the proto-gospel), so they may repent of sin and accept the pre-incarnate One God/ Christ as Lord (JN 8:42, 1JN 1:3-4).
At the moment of repentance/acceptance, God’s Holy Spirit (HS) enters believers’ spiritual hearts (RV 3:20), uniting them with God as heavenly Father (RM 8:9) and identifying them with Christ’s worldwide/catholic body or church (CL 1:18). As noted, Paul refers to the comparable moment for Abraham as spiritual circumcision. This manifold event is also called spiritual birth or baptism (1CR 12:13). We can infer that this dynamic occurs also for pre-NT believers like Abraham, because there is no salvation outside of Christ’s ekklesia or church (ACTS 4:12). Partial knowledge of God’s Word will limit ability to cooperate with Him, so
there is a need for evangelism or learning the full Gospel (MT 28:18-20, cf. ACTS 18:24-26) as well as for lifelong discipleship or spiritual training (2TM 3:16-17).
(You're quite welcome :^)