A criticism frequently leveled at the Church is that it is set in its ways and that - unlike science - new inputs have no impact on its tenets. In a word, the Church comes across as static, in a world whose rate of change increases and that adapts and adjusts itself continuously. The end result is the appearance of mismatch and alienation, and Church representatives saying things like “These are the teachings of the church and they’re unchangeable truths.” does not help.
There is a very serious problem with statements like the above though and I am just saying so from the perspective of the Church itself, rather than as a criticism from outside. The problem is that such statements negate Jesus' own words: “I have much more to tell you, but you cannot bear it now. But when he comes, the Spirit of truth, he will guide you to all truth.” (John 16:12-13). They deny “inspiration” received from the Holy Spirit and consider the Church's teaching to be an immutable monolith obtained in one go rather than the gradual understanding of its full revelation in the person of Jesus. In fact Pope Francis himself reminds us that “throughout the history of salvation, whenever God reveals himself, He brings newness — God always brings newness — and demands our complete trust” and then goes on to challenge us:
“Are we open to God’s surprises? Or are we closed and fearful before the newness of the Holy Spirit? Do we have the courage to strike out along the new paths which God’s newness sets before us, or do we resist, barricaded in transient structures which have lost their capacity for openness to what is new?”This is not to say that everything is open to change, but to be very clear about change being a core feature of Christian faith and consequently of the Church's teaching too.
“OK,” you say “but does the Church actually change what it teaches?” Instead of answering that with a categorical “yes” and a lot of handwaving, let me present the following, very specific, example that I came across by accident some time ago. It concerns the question of “mixed marriages,” which here refers to marriages between one Catholic and one Christian, but non-Catholic spouse.
Let's first look at how such marriages were spoken of in 1893, in Pope Leo XIII's Constanti Hungarorum encyclical:
“[T]o remove the source of many evils, it is of utmost importance that pastors never cease to admonish their flocks to refrain as far as possible from entering into mixed marriages. Let the faithful correctly understand and resolutely remember that it is their duty to regard with horror such marriages, which the Church has always detested. They are to be abhorred for the reason which we emphasized in another letter, “They offer the opportunity for a forbidden sharing and participation in sacred things; they create a danger to the religion of the Catholic partner; they are an impediment to the virtuous education of children and very often cause them to become accustomed to viewing all religions as equal because they have lost the power of discriminating between the true and the false.” (Pope Leo XIII, Arcanum)”Uff … “source of many evils,” “regard with horror,” “the Church has always detested,” “to be abhorred,” “impediment to the virtuous education of children [… who lose] the power of discriminating between the true and the false.” Sounds nasty!
Scroll ahead 100 years and look at what the 1993 Catechism of the Catholic Church says on the exact same subject (§1633-1637):
“[Mixed marriage] requires particular attention on the part of couples and their pastors. […] Difference of confession between the spouses does not constitute an insurmountable obstacle for marriage, when they succeed in placing in common what they have received from their respective communities, and learn from each other the way in which each lives in fidelity to Christ. But the difficulties of mixed marriages must not be underestimated. They arise from the fact that the separation of Christians has not yet been overcome. The spouses risk experiencing the tragedy of Christian disunity even in the heart of their own home. […] Through ecumenical dialogue Christian communities in many regions have been able to put into effect a common pastoral practice for mixed marriages. Its task is to help such couples live out their particular situation in the light of faith, overcome the tensions between the couple's obligations to each other and towards their ecclesial communities, and encourage the flowering of what is common to them in faith and respect for what separates them.”Hmm … “learn from each other the way in which each lives in fidelity to Christ,” “tragedy of Christian disunity […] in the heart of their own home,” “encourage the flowering of what is common to [the couple] in faith and respect for what separates them.” From abhorrently horrific, conscience-distorting evil to a challenging miniature laboratory of ecumenism where “fidelity to Christ” mutually enriches spouses - all in the space of 100 years. Not bad …