Based on the provided resources, the key points regarding the interpretation of Matthew 25:40 are:

1. The passage is part of Jesus' teaching on the Last Judgment, where he will separate the righteous from the unrighteous based on how they treated "the least of these" (Matthew 25:31-46). 1

2. Jesus equates serving the poor, the hungry, the thirsty, the stranger, the naked, the sick, and the imprisoned with serving Christ himself. As the Catechism states, "The duty of making oneself a neighbor to others and actively serving them becomes even more urgent when it involves the disadvantaged." 2

3. Pope Francis emphasizes that this teaching calls us to have a "preferential option for the poor" and to recognize Christ's presence in the poor and marginalized. He states that this is "a key criterion of Christian authenticity" and the mission of the whole Church, not just a few. 3

4. Pope Pius XII and the Compendium of the Social Doctrine of the Church also highlight this teaching, noting that Christians are especially bound to see the image of the Divine Child in the poor and to fulfill the duty of justice and charity towards them. 45

5. The Instruction on Respect for Human Life further reinforces this, stating that we are all called to recognize even "the littlest among the children of men" as our neighbor, following the example of the Good Samaritan. 6

In summary, the consistent teaching of the Catholic Church based on this passage is that we are called to recognize Christ in the poor and marginalized, and to actively serve and care for them as an essential part of our Christian discipleship and mission.