We are not required to participate in any particular devotion involving the intercession or invocation of the saints (though we are certainly strongly encouraged to do so by both Tradition and Holy Mother Church), but I disagree with those posters who have said “no” in answer to the OP’s question.
We are obliged to assist at Holy Mass, which, if we are uniting our own personal prayers to the public prayer of the Church, as the Church asks us to do, DOES involve the invocation of the saints at various points, particularly on feast days.
Jesus could simply appear to each of us face to face right now and proclaim the Gospel directly. Yet, He chose to send out his Apostles and establish a Church instead. Likewise, in the Old Testament, God could have simply appeared to all the people directly and given his Law…yet He chose to work THROUGH His prophets, particularly Moses. God has always and consistently worked through his ministers, whether angelic or human. If a Protestant can accept that God works through a human earthly evangelist who proclaims to the Gospel and baptizes (as just one example) a pagan, why is it so hard to accept that God could work through a human soul in heaven who now shares in His eternal glory and is even more perfectly configured to Christ than his ministers on earth are? Remember 2 Peter 1:4 - we have become partakers of the divine nature. This theme is repeated again and again in the New Testament. As St. Paul says, we are called to be COHEIRS with Christ. The saints in heaven have been mystically incorporated into the very divine sonship of Jesus Christ…they share in his eternal glory and in the divine life of the Trinity. This is why we can turn to them…God has chosen to share His divine life with them, and thus He takes pleasure in working working through them to assist us in our own earthly journey. Revelation 5 and 8 clearly attest to the fact that the saints in heaven, human and angelic, can offer up our prayers. I am a convert from Protestantism myself…God bless you in your search for the truth!
Check out these links:
scripturecatholic.com/saints.html