No, it is not sufficient to guide man to salvation, inasmuch as , firstly, it wasn't given to man from the beginning and , secondly, when it was given it wasn't the only authentic text, with regard to salvation of human souls, because before there was Holy Tradition. Many years before Moses began writing the first books of the Old Testament, there was a sacred piety in the community of people of Israel. Similarly, the books of the New Testament began to be written ten years after the formal foundation of he Church which took place on the day of Pentecost. The Church chose and sealed as inspired by God the books of the two Testaments over one hundred years later.It wasn't until the fifth century that we had the book called the New Testament as we now know it. In 419 AD there was a council of 217 Bishops who gathered in Carthage and who established a canon which determined the books to be included. The Book of Revelation remained in dispute for many years later and thus was not included in the lectionary of the eastern Church for reading in Church services.
Holy scripture is still the most important document in the Church. What we call Holy Tradition shows us how to interpret what it says. No one individual has the right or ability to interpret Scripture. This is reserved for the Church collectively. Think about how Christ gave out the information that is included in the Scripture. He gave it to His disciples, not to he masses, for them to teach. And so it is still to this day. Those who have been properly trained and received the gift of ordination have the ability to proclaim the teachings with the proper interpretations.
Elder Cleopa expresses it this way:
Our Apostle Paul says: " How shall they preach, except they be sent?" Accordingly, the bishops are the lawful successors to the Apostles and those went for the preaching to the people. Paul entrusts the heavy burden of the instruction of the people to Timothy and not to the faithful. He speaks of this elsewhere: "Are all Apostles? Are all prophets? Are all teachers?" Again he says to Timothy that the clergy must be "apt to teach" others. He does not, however, say the same thing for the faithful. He makes a distinction between shepherd and sheep, between teacher and those taught. Still, the teachers cannot each whatever they would like, but that which the Church teaches universally. They teach in the name of the church and of Christ. Not everyone has the intellectual ability and the requisite divine grace necessary to expound Holy Scripture correctly. The Apostle Peter also says this in his second epistle... "There are some things in them hard to understand, which the ignorant and unstable twist to their own distraction, as they do the other scriptures."We are bombarded in these times with many who call themselves Christians who believe that anyone can interpret scripture and who blatantly ignore the interpretations handed down by the Church and abhor the term Holy Tradition. They have made such distortions to the point of even rejecting the Sacraments, especially the sacrament of Holy Communion. The Holy Tradition of the Church is vast and rich allowing us to know the meaning of Scripture as it was intended by the Apostles. It includes much more than the Books of the Testaments. It also includes they teachings that have been incorporated in visual form in our icons and in hymnology as well as the writings of the Church Fathers. We must be cautious of Bible study programs that take place outside of the Church. Many introduce distorted teachings that not only negate the sacramental life of the Church, but also the ascetic practices such as fasting. The water down the Orthodox way of life as taught by the Apostles necessary for our spiritual growth in Christ.
Elder Cleopa warns:
Holy Scripture is like a very deep well wherein is comprised the infinite wisdom of God. If someone thirsty dives into this well to drink all of its water, he will be drowned within. If, however, he will fetch the water with a bucket and from there will drink from a cup, then there is not fear of being engulfed.He then reminds us of the Scripture passage about the eunuch of Candace, queen of the Ethiopians, who was reading the prophet Isaiah when the Apostle Philip asked him if he understood what he was reading. And he replied,"How can I, except some man should guide me?"
God revealed His word not to just anyone. Elder Cleopa explains:
He revealed His wisdom to those who , with respect to good works, were perfect and had innocence of infants. That's why Paul counsels the Corinthians as follows: "Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be ye men."Reference: The Truth of our Faith, pp 45 - 51