I believe this may answer your first question with regard to non-Christian religions:
The Jewish hasid or tsaddiq, the Islamic qidees, the Zoroastrian fravashi, the Hindu rsi or guru, the Buddhist arahant or bodhisattva, the Daoist shengren, the Shinto kami, and others have all been referred to as saints. https://en.wikipedia.org/wiki/Saint#Other_religions
However, we need to define what is meant (in Christian terms) by “saint.” The word “saint” comes from the Greek word hagios, which means “consecrated to God, holy, sacred, pious." The words “sanctified” and “holy” come from the same Greek root as the word that is commonly translated “saints.” Christians are called to be saints, (1 Corinthians 1:2) to increasingly allow their daily life to more closely match their position in Christ.
To the church of God in Corinth, to those sanctified in Christ Jesus and called to be holy…
The Protestant perspective is that all born-again Christians are saints, the body of Christ. The Church is made up of saints, followers of Christ Jesus who are still alive. The Bible also speaks of dead saints, those who have been killed because of their faith and their witness to Christ Jesus (Revelation 6:9-11). They wait until God says the time has come to avenge them.
How does the Roman Catholic understanding of “saints” compare with the biblical teaching?
In Roman Catholic theology, the saints are in heaven. In the Bible, the saints are on earth. In Roman Catholic teaching, a person does not become a saint unless he/she is “beatified” or “canonized” by the Pope or prominent bishop... In Roman Catholic practice, the saints are revered, prayed to, and in some instances, worshiped. In the Bible, saints are called to revere, worship, and pray to God alone. https://www.gotquestions.org/saints-Christian.html
From another source:
In Catholic, Eastern Orthodox, Anglican, Oriental Orthodox, and Lutheran doctrine, all of their faithful deceased in Heaven are considered to be saints, but some are considered worthy of greater honor or emulation. Official ecclesiastical recognition, and consequently a public cult of veneration, is conferred on some denominational saints through the process of canonization in the Catholic Church or glorification in the Eastern Orthodox Church after their approval. https://en.wikipedia.org/wiki/Saint
In many Protestant churches, the word saint is used more generally to refer to anyone who is a Christian. This is similar in usage to Paul's numerous references in the New Testament of the Bible. In this sense, anyone who is within the Body of Christ (i.e., a professing Christian) is a saint because of their relationship with Christ Jesus. Many Protestants consider intercessory prayers to the saints to be idolatry, since what they perceive to be an application of divine worship that should be given only to God himself is being given to other believers, dead or alive. https://en.wikipedia.org/wiki/Saint#Other_Protestantism
The problem with your question lies in the suggestion that having “saints” in a Christian religion is somehow cultish. If saints were worshipped, adored, prayed to or venerated, perhaps. But because the Protestant view of saints is that all born-again Christians who obey Christ and follow him are saints, that they make up the body of his church (a body of believers, and not any building or denomination), then there is no basis I can see for thinking there is anything cultish in acknowledging the existence of saints.