We Need the Holy Ghost

"I wish to remind my brethren and sisters … that we are dependent for our information and intelligence upon the Spirit of God, which may be in us, if properly cultivated, a spirit of inspiration, of revelation, to make manifest clearly to our understanding the mind and will of God, teaching our duties and obligations, and what is required at our hands. … We need assistance. We are liable to do that which will lead us into trouble and darkness, and those things which will not tend to our good, but with the assistance of that comforter which the Lord has promised his Saints, if we are careful to listen to its whisperings, and understand the nature of its language, we may avoid much trouble and serious difficulty."-Teachings of Lorenzo Snow pg. 77.

The Holy Ghost does not only testify that God lives, it does much more. It testifies the truthfulness of the gospel, he is a guide and protector. After King Benjamin gave his speech in Mosiah 2-4, the people felt the Spirit of Lord so strong that they said, "we have no more disposition to do evil, but to do good continually."-Mosiah 5:2. The Holy Ghost strengthens the desire to avoid evil but to do good continually.

The Lord says to Moses in Exodus 31:3,  And I have filled him with the spirit of God, in wisdom, and in understanding, and in knowledge, and in all manner of workmanship. In this verse, we learn that the Holy Ghost enhances skills and abilities.

Today, we are totally dependent upon the Holy Ghost. We need him to help us avoid trials and temptations or avoid traps which the adversary has laid for us. We need him to recognize those traps. We need him to help us become better servants of God.

Preach My Gospel chapter 4 provides more info. https://www.lds.org/manual/preach-my-gospel-a-guide-to-missionary-service/how-do-i-recognize-and-understand-the-spirit?lang=eng