2 Corinthians 1:11a NKJV - "You also helping together in prayer for us..."
Fruitfulness depends so much on prayer. This is God's way of working in and through a believer. You pray by spending meaningful time with your Savior and you will see fruitfulness in one form or another in your life. You also pray for others and they see fruitfulness in their lives and ministries. There's so much evidence that Christian workers who are prayed for are seeing the benefit in their work.
How many times I have heard or read of Christian ministers and missionaries who are seeing God's blessing on their ministries because of faithful prayer supporters upholding them before God! I encourage you with all my heart to read the great missionary stories of God's servants in our world over the past 250 years! It will amaze you how much was done in reaching the unreached. And only in heaven will we see how that happened. It wasn't just the servant in the field, but it was also due to the many supporters "back home" keeping the prayer fires burning!
When all is said and done, will your prayers have had a part in the salvation of lost souls and the fruitful ministry of God's servants? Or will your prayerlessness mean that not much fruit was gathered? Don't think you don't matter. Every Christian needs to understand their prayers are part of God's plan in reaching this world for Christ. Are you "helping together in prayer" for God's servants?