Source: runeslayer
Holy symbol will give you great blessings and more RS gold
The Holy Symbol is made from Unblessed Symbol which is made using a ball of wool with an unstrung symbol. Players with level 31 or higher Prayer skill are required to make Brother Jared from monastery blessed the Unblessed Symbol. Players can also bless the Unblessed Symbol themselves as long as their Prayer skill is level 50 and they have Holy book or Book of Balance. Selling the Holy symbol will give you more RS gold.
This guide require you to have enough RS gold to buy a lot of Unblessed Symbol until your inventory is full. Don’t worry, once you converted them into Holy Symbol, your Rs gold will be doubled. Head over to the Edgeville monastery. Find Abbot Langley and talk to him to join the Monastery. Go upstairs and talk to Brother Jared, he will be the one to bless all the Unholy Symbol into Holy Symbol. Head back to the Edgeville and sell your entire Holy symbol for RS gold.