Well, basically, Catholics commit themselves to the Sacred Tradition of the Church because it is out of this Tradition that Scripture came, because Scripture itself recommends and confirms this Tradition, and because nothing in Scripture says that this Tradition should cease to be authoritative in the lives of Christians once content from that Tradition was written down and canonized.
By "Sacred Tradition" I mean the various ways in which the teaching of the Apostles, the "deposit of faith," is passed on and preserved by the Church. This deposit was preserved and passed on through the writing of Sacred Scripture, which was inspired by the Holy Spirit, but it also was (and continues to be) preserved in the ordinary teaching of the successors of the Apostles (the bishops), in the writings of the early Church Fathers, in the authoritative documents of the Church (encyclicals, apostolic exhortations, dogmatic constitutions, conciliar canons, etc.), and in the liturgical worship of the faithful. Since the teaching and preaching of the Apostles has a divine origin, as does the consigning of that preaching to writing, both the preaching and the writing comprise the "Word of God" and thus "must be accepted and honored with equal sentiments of devotion and reverence" (Dei Verbum, no. 9).
Note that, whenever "tradition" is condemned in Scripture, for example, by Jesus (cf. Mt 15:3-9; Mk 7: 8-13) or by Paul (cf. Col 2:8), what is being condemned are the traditions of men, or traditions that are contrary to the Word of God. The authentic, Sacred Tradition of the Church, however, has its very source in Jesus Christ and is preserved by the Holy Spirit working in the Church. Surely you can see why I would not think that those verses apply, and really, in order to prove that they do, you would have to prove that some element of the Sacred Tradition of the Church was contrary to the written articulation of it in Scripture.
I hope that answers your question. There are many different ways to articulate what Sacred Tradition is, and what the relationship is between it, Scripture, and the Magisterium (or teaching office) of the Church. I highly,highly suggest reading the Catechism, nos. 74-95, and Dei Verbum (Dogmatic Constitution on Divine Revelation, from the Second Vatican Council) in full.
"And the prayer of faith will save the sick person, and the Lord will raise him up. If he has committed any sins, he will be forgiven. Therefore, confess your sins to one another and pray for one another, that you may be healed. The fervent prayer of a righteous person is very powerful." James 5:15-16
"Trust in the LORD with all your heart, on your own intelligence rely not..."
A - be audible. Speak clearly, do not mumble. Speak in a way that elicits interest in your sharing.
B - be brief. A good sharing can be made in 7 minutes or less. Try to target for this. Going beyond this time, in case a particular sharing has much significant content, should be the exception. Since the overall time for sharing is limited, this affords more people the opportunity to share.
C - be Christ-centered. Do not just tell a story, however interesting it may be, but relate everything ultimately to Christ. The sharing is meant to glorify God, not just amuse or entertain people.