I just wanted to chime in. I am a fellow sax player as well and I have been playing in church over 15 years now. Although you may feel like you have started late, this is a wonderful time to begin. There are so many more resources out there than when I first started. I must agree with the earlier post. One of the most important things is to develop your tone. The main thing in this is to make sure that you have good equipment. Make sure that you have a saxophone that allows you to play with the sound you want. Many top level saxophonists use selmer or yamaha custom. These are top of the line professional models and are very expensive. If you can get one, it is well worth it. I, myself, play a vintage selmer mark vi alto and soprano. Other, favorite brands include Keilworth and the Cannonball.
In addition, make sure that you have a mouthpiece that works for you. You must decide if you want a hard rubber jazz mouthpiece or if your embouchure is consistent enough to allow you to play on a metal mouthpiece. In terms of hard rubber mouthpieces, most musicians use meyer, lakey, or beechler. In terms of metal pieces, many musicians prefer dukoff, or beechler. The main thing is that you experiment and find a mouthpiece and reed combination that works for you. You can call a music company named the Woodwind and Brasswind and they will let you tryout mouthpieces on a mail order basis. Remember, the more open the mouthpiece, the softer the reed. The more closed the mouthpiece, the harder the reed should be. Strength four and five reeds really should not be used in this setting unless you shave them down enough to play on.
I would recommend that you begin by making sure that you develop you ears and technique. When I say technique, of course I am talking about the speed of your fingers. Make sure that you know all of your scales. No ifs, ands, or buts about it. Know ALL majors and minors. Learn the diminished, half - diminished, whole tone, and diminished whole tone. Also, be comfortable with blues scales and pentatonics and their various permutations. Make it your goal to play all of the major and minor scales in scale-tone seventh chords, thirds, fourths, fifths, etc throughout the entire range of the instrument. Remember, you can not play all of the great things that you may hear if you don't have the technique to do so.
From a listening stand point, there are many great gospel saxophonists out there that many people may not know about. Do research and find their cds and listen as much as possible. On the top of the list, I would recommend Donald Hays. He has played with everyone from Ben Tankard to Yolanda Adams to the Colorado Mass Choir. As a matter of fact, you have probably heard him, but don't realize it. Of course, Angella Christie is out there as well. Other gospel sax players include Harold Rayford, Tony Smith, Rod Tate, John Lynch. Also, if you are looking for a tradition sound, check out Vernard Johnson and Jerone Lee. Also, young phenom making a name for himself is Jarrett Johnson. Get there cds and listen and copy what you hear. I hope this helps. Good Luck.
jremon aka Saxman1