Christians need not struggle to find the purpose of life. As Christ's followers, we have been given a direction, which is heavenward; a life's purpose, which is to glorify God; a life's goal, which is to become like Christ; and a life's mission, which is to spread the Gospel to all of creation.
Every Christian is mandated to preach the Gospel to all creation (see Mark 16:15). It's our task to spread the message of the Lord Jesus Christ, the very same message that saved us. More than that, we are to make disciples of all nations, teaching those who will believe the very things that the Lord Jesus Himself taught. (see Matthew 28:18-20
As such, we must realize that preaching the Gospel is the work that all of us should be doing. It's not just for preachers, evangelists and pastors. It's for all of us.
That said, we must do our best in preaching the Gospel to all men. It is indeed challenging, but it is extremely fulfilling and satisfying to see a person repent and believe in the Lord Jesus Christ, because we preached Him to them. It really is.
Encouragements for all who will preach
To help you get motivated to preach the Gospel, here are a few things to remember. These truths will excite you, release you from certain fears related to preaching the Gospel to others, and will hopefully motivate you to make it your life's goal.
1) God is waiting for people to seek Him
"Seek the Lord while He may be found, call upon Him while He is near." (Isaiah 55:6)
Friends, it is important to know that when we preach the Gospel, we have God working alongside us: our job is to preach, and His role is to show up.
In Mark 16:17, the Lord Jesus Himself said that some "signs will follow those who believe" in Him. When we preach Him to others, He will show up. When the people respond to our preaching of the Gospel, He will show Himself to them. He promised that.
2) God will forgive the repentant - always
"Let the wicked forsake his way, and the unrighteous man his thoughts; Let him return to the Lord, and He will have mercy on him; And to our God, for He will abundantly pardon." (Isaiah 55:7)
Friends, we should be excited to preach the Gospel to all men because through it, the repentant will be reconciled with God. 2 Corinthians 5:18-19 tells us that God "has given us the ministry of reconciliation." Our work is bridging the gap between Him and people, in an effort to tell men that God loves them, and that there's a way for them to come back to Him: Christ Jesus.
As Christians, "we are ambassadors for Christ, as though God were pleading through us: we implore you on Christ's behalf, be reconciled to God." (see 2 Corinthians 5:20)
3) God has bigger plans than us - including who He will save
""For My thoughts are not your thoughts, nor are your ways My ways," says the Lord. "For as the heavens are higher than the earth, so are My ways higher than your ways, and My thoughts than your thoughts." (Isaiah 55:8-9)
Many of us make the wrong assumption that certain people will never be saved, and thus "it's a waste of time to preach the Gospel to them." This is so wrong, not to mention sinful.
While man has a "criteria" of sorts regarding who gets to be saved, God only has one: Jesus Christ. Anybody who believes Him gets saved, period (see John 3:16). Regardless of a person's past, he can be forgiven if he comes to God in repentance.
Whether a person is rich or poor doesn't matter. Whether a person is good or bad doesn't matter. When a person comes to Christ, he repents of all his sin and starts anew. Anybody can come to Christ a sinner, but no one continues in Christ remaining a sinner - He makes us into a new creation, His Holy Spirit sanctifies us and makes us holy and Christ-like, and we are all transformed from glory to glory as we behold Him face to face. (see 2 Corinthians 5:7; 1 Corinthians 6:11; 2 Corinthians 3:18)