Spiritually mature Christians adjust their attitude and mindset onward; they have a forward looking mindset. We are to follow Paul’s and other mature Chrisitan's example of making spiritual things a priority in their lives by developing an upward perspective.
Paul leaves Thessalonica after only 3 weeks and into that vacuum of leadership comes accusations leveled against him. He uses chapter 2 to defend how he ministers and gives us a brilliant path to follow.