Here is just a reminder from Psalm 40 of what we are supposed to do with the Gospel:
I have told the glad news of deliverance
in the great congregation;
behold, I have not restrained my lips,
as you know, O Lord.
I have not hidden your deliverance within my heart;
I have spoken of your faithfulness and your salvation;
I have not concealed your steadfast love and your faithfulness
from the great congregation.
God has delivered us out of the pit of destruction and set our feet upon the rock, and that Rock is Christ. He has provided such a great salvation for us that to not declare it to others would be absolutely unloving. Notice that David says that he will declare the salvation of the Lord to the congregation. Obviously, the lost need to hear the word of Christ, but so do those who profess to follow Him. We need the Gospel for both our salvation and our sanctification (becoming more like Christ). We cannot become better people under our own power. We are not saved by grace and then sanctified by works. We are made better only by the power of God. He is doing this great work in us and He will see it through to completion.
We need the Gospel everyday. We need to be reminded of it, and we need to remind others of it.