Back when I was in first grade, my elementary school would celebrate the end of the school year with a demonstration of the sixth graders' science projects. It was awesome. It was particularly cool because I knew that one day I would be a sixth grader, and the prospect excited me. See, from the perspective of a first grader, sixth graders fall into the same category of Big People as teenagers and adults, but unlike those two, being a sixth grader actually seems attainable. Adolescence was just as distant a dream as adulthood at that point.
I bring this up because I think it provides some necessary perspective on our concept of "the saints." God has destined us for greater things than we can possibly dream. He created us, He called us, He justified us, and He will glorify us (Romans 8:30). We are therefore in the position of first graders in the cosmic scheme: even 'adolescence' (the interim glory of the intermediate heaven) is beyond our comprehension, let alone the 'adulthood' of the New Heaven and New Earth.
Fortunately, God gave us role models for our encouragement, that they reflect His glory in ways we might not have been able to otherwise comprehend, to allow us to glimpse even through the veil our future fate in His Presence. The saints are, by this analogy, in the position of the sixth graders: the testimony of their astoundingly holy lives gives us hope, for they are not so far removed from our own experiences as to be out of reach. Naturally, by now they've moved on to adolescence, but we remain children, and we can only see the testimony of their mortal lives.
One of the five "solas" of the Protestant Reformation was "Soli Deo gloria" -- "Glory to God alone," as opposed to glory to any created being. This is a noble idea, as far as it goes, but it can be easily taken to extremes.
Some virulent anti-Catholics cite Matthew 23:9 to attack Catholics who call priests "Father" as a term of respect. Yet they seem to forget the the passage ostensibly condemns any use of the word "father," presumably including its application to our biological male parent. This is nonsense. Matthew 23 was a discussion of how to respond to the authority of the rabbis and Pharisees -- who, though they sinned against the commands of the Law they promulgated, still sat on Moses' seat and still commanded authority under Jewish tradition. Jesus' words were a call to humility and a reminder that authority owes its own legitimacy to God, and that pride has no place among those who are called to greater responsibility. His words do not undermine the commandment to "Honor thy father and mother," nor could Christ have contradicted the words of the Law, for by the Shema, "Hear, O Israel, the Lord our God, the Lord is One."
The modern instinct for egalitarianism is necessary in a legal sense, for a free society requires an impartial rule of law. But in its cultural applications, this modern instinct is disastrous. Peter Kreeft described it as a new manifestation of pride: rather than elevating oneself above all others, it would tear down all others who would dare to be elevated above oneself.
In a society such as ours, respect for authority is a practical necessity, just as respect for tradition is necessary in an age that venerates modernity at the expense of the past.
Glory belongs solely to God, but God has chosen to glorify us, His children. Only Christ was the Son of God, but by His wounds we have been made sons of God, and brought into our inheritance. Clearly we ought not worship anything other than the One True God, for that would be idolatry. But Catholic doctrine distinguishes between dulia (honor and veneration for anything created) and latria (worship and adoration pertaining to God alone), and surely this distinction should seem natural to us. For I respect and admire Pixar studios for their near-unfailing ability to craft comic and dramatic masterpieces, but this is a far different kind and level and admiration compared to that which I bear towards my God. There are degrees of honor and veneration that are appropriate to created things, to the degree that they bear witness to their Creator.
The Church has no power to make or declare saints. The process of beatification and canonization are processes of recognizing saints -- that is, recognizing those whose lives were a dynamic testimony to the manifested fruits of the spirit, such that we know with certainty that they live now in the Presence of God. This understanding helps us understand why veneration to the saints is appropriate.
In the book of Revelation, John is visited by an angel, one who dwells in the very Presence of God. The appearance of this angel is enough to drive him to his knees in awestruck wonder. The angel cautions him not to worship him, for worship belongs to God and not to His servant, but surely John's reaction was understandable. Our weak eyes are easily blinded by the sun.
The saints are those who lived to reflect the glory of the Lord, and God's glory shone through them. How could we not respect and honor their witness? Those of us who grew up in a Protestant background understand the oppressive fear of committing idolatry, the fear of offending God by offering to others what is due solely to Him. But when we see that honor is due to the saints precisely because of they manifested the glory due solely to the Lord, we should feel safe in offering our respect and appreciation for their lives. Christ was the firstborn, but we have plenty of older brothers and sisters who, in following Him, lead the way for us.