Lack is not having enough of something. Lack is falling short of something. We experience lack when we fall short of actual or perceived tangible and intangible resources we need for living: spiritually, financially, emotionally, psychologically, intellectually, experientially. Lack affects our joy and is experienced in the form emptiness, doubt, uncertainty, anxiety, worry, fear, perplexity. And these are emotions and feelings that we are always running away from, and are naturally inclined to seek abundance, sufficiency, growth, comfort, and productivity—the absence of lack. But what do we do when we experience lack, when we experience emptiness and doubt, when we fall short of our goals in our pursuit of spiritual, personal, relational, emotional, professional excellence? After all, lack is the natural familiar state of all humanity, for Christian and non-Christians alike. There is bad and good news for you Christian.
I am realizing how crucial the books of the Old Testament are to understanding the significance of Jesus Christ in the New Testament. So before I go any further, I strongly encourage you to go back and read the Bible from the beginning. A good plan to start with is the Youversion Chronological Bible Reading Plan.
Now to the topic of this post. At times I am amazed at how quickly I intentionally and unintentionally blur the reality, holiness, mercy, grace, and conviction of God in order to pursue my own will. A lot of times, due to utter disobedience, lack of patience, lack of faith, lack of commitment and faithfulness, I will do that which is in complete opposition to the will of God--in other words, I sin. Sometimes it's a private sin (no one is there to witness), and other times it's a public sin. When going through this phase, and especially when coming out of any sin, I get hit like a ton bricks when I realize just how quick I am to forget.
God's chosen people of Israel, after being saved from slavery in Egypt, witnessing the presence and love of God in every single possible way, after being led through a desert to a land that was promised to their forefathers, rebelled multiple times against their source of life, provision, and guidance. The book of Exodus chronicles the beginnings of this rebellion with the root of sin starting from Adam and Eve. As the book of Exodus concludes, there's an ugly picture of the human sin condition. The book of Exodus ends with the second most vivid picture (the first picture being Jesus Christ) of the covenant between God and people. In what is supposed to be the most holiest, meaningful, beautiful celebration of the convenant between God and his people, a big stain of sin is cast onto the picture when God's people outrightly rebel by impatiently choosing to worship a piece of gold shaped in the image of a cow, as they had learned and seen as slaves in Egypt. Read the entire book of Exodus (but more specifically chapters 32) to see this picture of sin, mercy, and the commitment that God still kept with His people after this grave sin of idolatry, which is the basis of all sins.
How easily they forgot the salvation of God. They were rescued from over 400 years of slavery, protected as the Egyptians were plagued, led through the desert, the Red Sea, protected from the Egyptians' pursuit, supernaturally fed, and many more wonders of God. The Israelites had previously agreed to do everything God commanded them to do just what seemed like a few days before their rebellion (Exodus 24:7). They had been given the 10 Commandments (Exodus 20), and so they knew well the expectations of God. Keep in mind that the first few commandments address the sin in which they walked (not fell) into, with the help of Aaron, who was Moses's right-hand man in leading the people to the Promised Land. Aaron is the one that gave in into the people's request to make the golden "god", shaped the metal, and later when Moses came back, awkwardly and untruthfully gave an account of how things happened, mentioning that he simply threw the gold in the fire and it came out as a golden calf. Sounds anything like the excuses we make before, during, and after sin? I think it does. We formulate all sorts of justifications for why we give into public sin (often citing we couldn't handle the peer pressure), and private sin (citing our weakness, blaming someone in our past, etc).
In conclusion, this is the picture of sin against the background of the Most Holy God. The same Israelites we see in Exodus are as human and as sinful as it can get. Even more, they were not any worse or better than us today.
Since the creation, as evident in Genesis, sin is our default state. God has always been merciful but yet has remained consistently just when the sentence and price of sin had to be paid. Even in his judgements, his mercy is ever present (e.g. the death of Jesus Christ).
I once again encourage you to read the Bible from beginning to end. It can be time consuming (keyword "can be", if you don't manage your time well) but is crucial to your growth.