Must one believe in the Trinity to be saved? This is perhaps one of the most popular objections to the doctrine, even though it does not address the positive evidence for the Trinity in Scripture. The objection is sometimes stated in a more complex form: If belief in the Trinity is essential for salvation, why is the doctrine not clearly or plainly set out, in so many words, in the Bible? Why does the Bible never say “God is a Trinity” or “There are three persons in the one God,” or something equally explicit as an affirmation of the doctrine? And if no such statement is there in the Bible, how can belief in the doctrine be essential for salvation?

The short answer is that it is not quite accurate to say that belief in the doctrine of the Trinity is essential for salvation. Doctrinal accuracy on any theological subject is in any case at most a litmus test or barometer of the genuineness of a person’s salvation, not a prerequisite for receiving the gift of salvation. There is no theology exam on which a person needs a passing score before God will accept that person’s trust in him for salvation. We are saved by God’s grace through faith, that is, through our trust and reliance on God’s gift of salvation in Christ (Rom. 3:21-26; Eph. 2:8-10; Tit. 3:5-8). On the other hand, deviation from the basics of sound Christian doctrine can be evidence that a person is either immature in faith (see Acts 18:25-26) or has not genuinely come into a saving faith relationship with Christ (Rom. 16:17-18). Resistance to doctrinal correction would generally be a tip-off that the latter problem is the case.

That having been said, what does the Bible tell us we need to know about the Trinity? Obviously, it does not tell us that we need to use words like Trinity or formulas like three persons in one God. These do not appear in the Bible. On the other hand, we are expected to make a faith commitment to the three persons of the Father, Son, and Holy Spirit, as is evident from the injunction to make disciples by “baptizing them in the name of the Father and the Son and the Holy Spirit” (Matt. 28:19). Someone who denies that the Son is a divine person or who refuses to honor the Son with religious devotion, reverence, and worship, is giving evidence that he or she has not made that faith commitment and so has not yet come to a genuine relationship with the Son. Jesus himself stated, “Unless you believe that I am [he], you will die in your sins” (John 8:24). This means, minimally, that we must accept Jesus for who he really is if we are to be assured of salvation. So, if Jesus is indeed God incarnate, as the Bible does in fact teach, then we need to know and accept this truth about his identity.

Those who are saved as Christian believers, then, will have faith in the Father, Son, and Holy Spirit as God, although they may not be able to articulate this in a doctrinal way very well at first. As they come to understand what the Bible says about this subject in conversation with the rest of the church, such believers normally will assent to the doctrine of the Trinity as the church’s historic and best articulation of the divine nature and relations of the Father, Son, and Holy Spirit.

If a person rejects the doctrine of the Trinity, that person has cut himself off from the church. It is interesting to note that all of the major (and as far as I know all of the minor) heretical religious versions of Christianity agree on one thing: they all reject the doctrine of the Trinity. This does seem to be the crucial, decisive theological issue separating orthodox from heretical forms of Christianity.

Is it possible for someone in a non-Trinitarian religious group to be saved? Yes, it is possible, but it isn’t recommended. Again, doctrinal error may be a sign of spiritual lostness, or of spiritual immaturity, or perhaps of some other type of problem, and we aren’t in a position to judge definitively whether other people are saved or not. Nevertheless, we cannot compromise on so basic a doctrine as the Trinity; we have a responsibility to take a stand for the integrity of the church’s teaching. We can do so with full confidence that what we are defending is biblical, because all of the essential elements of the doctrine of the Trinity are clearly taught in the Bible.