Matthew 5:3 in the New World Translation (2013) reads: “Happy are those conscious of their spiritual need, since the Kingdom of the heavens belongs to them.” (Other translations) As noted in the link for other translations, they render being “conscious of spiritual need” as being “poor in spirit.” The Amplified renders that as those who are humble, rating themselves as insignificant. All of them conclude that because of this condition, they can claim the Kingdom of heavens as their own.
But is it really as simple as that? Would Jesus really be so superficial as to say that all we have to do is be poor in spirit, just to be aware of spiritual need but take no proactive action to handle that need? If you are thirsty or hungry, your body makes you very aware of that need. If all you do is give it a passing acknowledgement, does that take care of the need? No, it does not. What would a person who is aware of any “need” do? They would act on it. What would a person do that realizes their inborn spiritual need? Just like physical food and drink, they would seek to be nourished. Hence we can call to mind the action Jesus recommended: “Be my follower.” What is involved in being a follower of Jesus? In one word, obedience. Yes, obedience and attentiveness to direction are needed.
The word conscious is defined as being "aware of and responding to one's surroundings," “being fully aware or sensitive to something; having the mental faculties fully active; deliberate and intentional.” If we are fully aware, sensitive to, and responding to our “poor spirit” or “spiritual need,” we will seek out and fully perform (deliberately and intentionally) the will of God. Then indeed, we can be confident that we will be rewarded with the Kingdom of the heavens. So this is not something that we can merely passively acknowledge and then go on our merry way.
So then, putting Matthew 5:3 in context with the rest of Jesus’ words and in terms that we 21st century folks can appreciate: Happy are those who realize and act upon their need for meaningful relationship with their God and his designated King, Jesus Christ. Those who are fully committed and unreservedly obedient can rest assured the Kingdom of heavens is theirs.