One thing that struck me about Exodus 23 was that God was practical. Yes, He commanded the Israelites to drive out the Canaanite et al, but they would need to be persistent as this would not be a quick or one time thing.
v29-30 I will not drive them out from before you in one year, lest the land become desolate and the wild beasts multiply against you. Little by little I will drive them out from before you, until you have increased and possess the land.
Makes perfect sense. Though not stated in this passage, it is also a test of the Israelites endurance and their willingness to obey even at the cost of great personal sacrifice for an extended period of time. It would test their desire to drive evil from their land. Tests they would ultimately fail. Just like we do in so many ways. Thankfully, God's faithfulness to us is not dependent on our faithfulness to Him. We cannot obey perfectly and He knows that - that is, after all, why we needed a Saviour!
In chapter 24, Moses, Aaron, and his sons, and 70 of the elders take part in fellowship and communion in the very presence of God! We know that no human can see God fully face to face and live (because of His holiness and our sinfulness), so we know this was only a partial viewing of God - perhaps only under His feet as that is all that is described in this passage. But either way - can you even imagine what that experience would've been like?! What an amazing privilege! And how horrible that they could go to that mountain top experiences to the disaster of the golden calf in only 40 days. Over and over we are battered over the head with our need for a Saviour. We are no better. As much as we'd like to think so, we really aren't.
Our Thessalonians passage is mainly Paul reassuring the Thessalonians that they hadn't missed the Second Coming, and explaining more of what would happen beforehand.
I appreciated my ESV Study Bible's note on 2 Thessalonians 2:13 which says
But we ought always to give thanks to God for you, brothers beloved by the Lord, because God chose you as the firstfruits to be saved, through sanctification by the Spirit and belief in the truth.
Note the involvement of each person of the Trinity: the Father elects, the Son loves, and the Holy Spirit makes holy.
The trinity is a hard concept to grasp, but what a wonder it is!
Tomorrow's Bible In a Year Passage passage: Exodus 25-26, 2 Thessalonians 3