Arguably, the apostle who speaks of love more than any other is the apostle John. He speaks of God's love for His people and records the commands of Christ that we ought to love one another. In his epistles, he argues that no one who does not love his fellow Christian can be said to love God, and that God is love.
Yet, John also records to us other words of Christ that indicate that Jesus is the God of the Old Testament, that He and the Father are One, that He is the God who existed before Abraham came to be, and most importantly for our discussion, that He is the God who spoke to Moses in the exodus event.
In fact, I want to zero in on that last idea for a moment. In John 8, Jesus identifies Himself as the God of Abraham and Moses by saying that Abraham had a relationship with Him, saw His day, and was glad. He then tells us that even before Abraham He is ego eimi "I AM." This is a clear reference to the I AM statement in Exodus 3, where Moses encounters YHWH, which is likely derived from 'eyeh "I AM."
In that narrative, YHWH tells Moses that He is going to force Pharaoh's hand in giving up His people and will harden his heart to display His glory to the nations over a rebellious people. We all know that this foreshadows His plagues upon Egypt that culminate in the deaths of the firstborn children of the Egyptians (a lex talionis judgment on God's part for Pharaoh's unjust killing of the Israelite baby boys).
It is this YHWH who kills the firstborn sons of the Egyptians, and then proceeds to guide Israel in their war against the Amalekites as well as to instruct them to destroy the Canaanites.
Rather than disassociate Himself from the God of this narrative, Jesus tells us that He is YHWH. In other words, He is the God of that narrative.
In fact, everyone reading John's prologue would understand that when John said that the Logos = the Son was God, that He is to be understood as the God presented in the Old Testament, specifically in the Pentateuch upon which John builds his Gospel. The Son is the God of Abraham and Moses, the God who reigned fire on Sodom and Gomorrah, the God who struck down the firstborn children in Egypt, the God who slew the Canaanites and ordered their destruction as a people.
The argument John makes of the Logos assumes the Wisdom tradition in what I call a "priority argument" that presents the Son as the Personified Divine Wisdom upon which the Torah is based. Hence, Jesus' authority is greater than Moses' authority, not because they teach two different things, but because the Son is the wisdom upon which Moses' commands are rooted. Hence, the Torah is a direct product of the Father through the Divine Person of the Son. That means that the commands therein are not antithetical toward who the Son is and what the Son teaches, but in continuity with who He is and what He teaches. He teaches the fullest expression of it, revealing the Father in fulness, whereas the law was only a partial, not inaccurate, revelation of Him. Hence, the Torah is to be read as rooted in God who is love, rather than read, as many attempt today, as antithetical toward what is loving. The commands in the Torah, even the ones that command the slaughter of enemies, is rooted in the wisdom of the Son and reveals the love of the Father.
John, therefore, isn't saying that Jesus is a different kind of God. He's not another God. Nor is he saying that Jesus is love and the God of the Old Testament is not love. What he is saying is that God is love and the God of love is the same God of the Old Testament, the same God who annihilates the wicked.
This means two things:
(1) That Jesus cannot be used to pit one view of God against the other (i.e., the view of God in the NT versus the view of God in the OT), as they are one and the same. The person who attempts this has, therefore, in the eyes of the Gospels, got his reconciliation of the Old and New Testaments wrong.
(2) The terrifying judgments of God in the Old Testament need to be understood in terms of God's love for His people. God is love refers to what God is for His people. Love must choose between agents of life and agents of chaos, and God chooses His people over agents of chaos who would destroy them. Hence, every judgment of God is an act of love toward His people, and to understand them differently is to misunderstand what God is doing, who He is, and what love for a group of people really looks like in threatening situations.
The gnostics tried to create a different God out of Jesus than the one in the Old Testament as well. They wanted to present a Jesus according to their own culturally-derived religious and philosophical sensibilities. But John tells us that this is the spirit of Antichrist (i.e., replacing the real Jesus Christ with a different one). Those who are not born of God attempt to replace Christ with one more philosophically palatable, but those who are born of God know the real Jesus, and therefore, listen to them, not to those who speak "according to the world" (reading 1 John 4:1-6 here would be instructive).
In other words, if one is to "listen to us" (i.e., the apostles), rather than the false prophets of antichrist, who replace the real Christ who is the God of the Old Testament, with another Christ who is a creation of their own lopsided view of what love should always look like, regardless of the situation, then one needs to view Christ as they viewed Him, as they remember His own statements about Himself. He is not a god of the Bible, i.e., the nice loving one as opposed to the mean wrathful one. He is the God of the Bible, and if you are one of His people, He is nothing but love to us; but if you are not, it is a terrible thing to fall into the hands of the living God. And that terrifying God is the Son into whose hands all judgment has been placed, and through whom a terrifying end to the wicked world will be brought about when He returns and slays His enemies and casts them into the fire.
Here, we would be wise to take John's words well. The apostles actually knew Jesus. They saw with their own eyes. They touched Him with their own hands. They heard Him with their own ears. The false prophets have not. They speculate about Him, but John and the other apostles knew Him.
So I ask you this: Are we to understand Jesus as the modern liberal understands Him, as polemical toward the God of the Old Testament, specifically the Pentateuch? Or should we understand Him as the apostles have understood Him, as the God of the Old Testament who does not disassociate Himself from the God of that narrative, but rather identifies Himself as One with the God of that narrative?
As John tells us, he who does not have the Spirit of God will not listen to the apostles. Only he who has the Spirit of God will. Which one are you?