“I am who I am.” The Hebrew can be translated “I am who I am” [or: I am that I am], or “I will be what I will be” [or: I will become what I will become]. All of these are good translations of the Hebrew, and all of them apply. “I am” is true both now and in the future: God is an ever-present reality now and in the future; both now and then He is the “I am.” God was, and is, and is to come. This “name,” is clearly related to the proper name of God, Yahweh, (actually YHVH) because it is derived from the trilateral root (H-V-H), which is from an earlier root (H-Y-H) “to be.” Even that does “double duty,” because it can both refer to God, who is Eternal and who “is,” and it can refer to what He will become and do.
God “is” in that He is an ever-present reality. God is also “I will become what I will become” in several different senses. One of those is that God will become what His people need Him to become for them: the provider, the deliverer, the comforter, etc. On the other hand, God will become what He Himself “will become,” apart from human condition or desire. He is God and Creator, and He is not subject to the will and whims of humans. He will become what He will become according to His plan, wisdom and desire.
God’s proper “name” is Yahweh, but when asked His name, He did not say, “Yahweh,” He said “I am who I am” (“I will become who I will become”). This shows us that God’s name Yahweh is intrinsically connected to His character, which is multifaceted, and cannot be simplified into a simple name or concept, such as “God is love.” While He is love, He is much more than that.
Although almost all English version have “I am that I am” as the translation of Exodus 3:14, a number of versions have “I will become [or “be”] what I will become” as an acceptable translation and put in a marginal note to that effect (cp. CEB; HCSB; ESV; NAB; NET; NIV; NLT; NRSV).
It is sometimes said that Jesus claimed to be God in John 8:58 and said he was the “I am,” but that is not the case at all (see commentary on John 8:58).