The character of God has been brought into question since the very beginning. Is God who He says is? Or does He change depending on the situation? The consistency of God is further brought into question with the apparent change in nature in the God of the Old Testament and the God of the New Testament. The bible declares that God doesn’t change (Malachi 3:6), so why does it appear that God and Jesus are different if they are meant to be One (Deuteronomy 6:4, Mark 12:29)? Did the Old Testament writers merely mishear God and write things about Him that are mistaken? Or perhaps we need a more careful reading of the scriptures to see that God hasn’t changed.
The Trinitarian God
The scriptures declare that there is one God, but unique to Christianity is the fact that this God exists in three persons. These three persons are co-equal, interdependent, and unified with the same nature but distinct in roles. This is what Christians refer to as the Trinity – One God in three persons. This is important because if each person of the Trinity has the same nature then One person cannot act in a way that would contradict the act of another. Furthermore, if One of the persons within the Trinity were to make a decision there would have to be total agreement since there is complete oneness within the Godhead. For example, the Trinity decided to make man in their image (Genesis 1:26). There was complete unity when making that decision and there is complete unity within the Trinity when making every other decision. Here is where the confusion lies, I think. Throughout the scriptures, God acts in different ways at different times. Sometimes it appears God has acted wickedly and other times He acts kindly. The confusion occurs when we separate God’s ways from God’s nature. God can and does act in different ways but He never acts in contradiction to His nature. So, what is His nature?
Is God Different?
Since creation, God has been progressively revealing Himself to mankind with this revelation culminating in the person of Christ (Hebrews 1:1-4). God’s plan from eternity past was to redeem a people for Himself, through His Son. So that these people can know Him and enjoy Him forever (Ephesians 1:3-10). Throughout the scriptures, God reveals much of His nature as the biblical story unfolds. After the Israelites committed idolatry causing Moses to break the ten commandments, God brings Moses back up Mount Sinai to re-write these commandments on new stones (Exodus 32). As Moses enters the presence of God, see how God describes Himself “The LORD passed in front of him and proclaimed: The LORD—the LORD is a compassionate and gracious God, slow to anger and abounding in faithful love and truth, maintaining faithful love to a thousand generations, forgiving iniquity, rebellion, and sin. But he will not leave the guilty unpunished, bringing the consequences of the fathers’ iniquity on the children and grandchildren to the third and fourth generation”. (Exodus 34:6-7). This isn’t merely how God describes Himself, this is also how the people of God describe God (Daniel 9:9; Isaiah 30:18, Joel 2:13, Jonah 4:2). Repeatedly, we see that the God of the Old Testament is merciful, kind and patient. So why does He kill so much and Jesus didn’t at all? There are a few problems with this question. 1) It separates God (The Father) and Jesus. Remember they have the same nature and are eternally unified. In everything, they are in total agreement. 2) It disregards covenants. God dealt with different people in different ways at different times. All of His ways are consistent with His nature. 3) It disregards sin. God doesn’t kill people out of uncontrolled rage, God isn’t abusive. God is Holy and Just. God hates sin and responds to it with His wrath, occasionally enacting immediate justice to deal with sin, purify His people and remind them of their call to holiness (Nahum 1:2, Leviticus 18:29-30).
Jesus is the perfect revelation of God, He isn’t the replacement revelation of God. Jesus didn’t come to correct the misrepresentations the people under the old covenant had, but to be the One that inaugurated a new one (Hebrews 8:6). God used patriarchs, prophets, judges and kings, sacrifices and other means to point to the coming of His Son who will be better than all these things. Jesus didn’t come to say disregard what you first knew, He came to say this is what you have been waiting for and it’s better than what you can imagine. The reason His people rejected Him wasn’t that God of the Old Testament was angry and Jesus was so mellow; they rejected Jesus because they hated the light (John 1:9-11, 3:19-21). Jesus affirmed the same oneness that God declared in the old testament (John 10:30). And when Jesus says He only does what He sees the Father do, He is referring to His role within the Trinity not discounting certain acts God the Father did in the Old Testament (John 5). Jesus had no issue with how God acted and interacted with His creation, so why do you?
Admittedly there are some difficult portions of scripture to handle. If you are finding it difficult to reconcile the God of the old testament and the God of the new I understand. There are some texts that you will have to wrestle with. Fortunately, our salvation is not contingent on understanding the immutability of God. Salvation comes by believing in Jesus Christ. Believing in Jesus Christ means believing in who He says He is and what He says He has done. Believing in Jesus Christ also means believing that He doesn’t change (Hebrews 13:8). There is no difference between God the Father and God the Son, they are and always will be perfectly One.