In many traditional Christian religions and as defined by the Merriam-Webster dictionary; a saint is someone who is holy or virtuous and typically regarded as being in heaven after death.
Thus, from the outside looking in one might feel that members of The Church of Jesus Christ of Latter-day Saints are being presumptuous by calling themselves saints.
Our view of the word “Saint” is different. By referring to ourselves as saints we do not mean to suggest our immortality or status in heaven is guaranteed or that somehow our acts have set us aside to be worthy of prayer or worship.
We use the word Saint the same way the apostles did in the New Testament, referring to all those who by baptism have entered into the Christian covenant. (see Acts 9:13, 32, 41; Rom. 1:7; 1 Cor. 1:2; Philip. 1:1; 1 Pet. 1:14-15)
Thus members of the church are saints in the sense that we have entered into a covenant to follow Jesus Christ and follow his commandments and we would openly use the term to include anyone who has done the same.
The word saint in Greek denotes “set apart, separate, [and] holy.”1 If we are to be Saints in our day, we need to separate ourselves from evil conduct and destructive pursuits that are prevalent in the world.Quentin L. Cook – Member of the 12 Apostles
We pray only to God the Eternal Father in the name of his son Jesus Christ and understand that we must follow His commandments and strive to endure to the end of this mortal life.
So who is a saint? A Saint is one who follows Christ in holiness and devotion with a view on eternal life. If we are to be worthy Saints, we should minister to others and adhere to the Savior’s admonition to love God and our fellowmen.