In Luke 9:61-62 (ESV), Jesus replied to a man who said, “‘I will follow you, Lord, but let me first say farewell to those at my home.’ Jesus said to him, ‘No one who puts his hand to the plow and looks back is fit for the kingdom of God.’” 

A plough or plow is a tool to prepare a field for planting. It is used for work. So, If anyone wants to work in God’s service, he must focus his energies on serving (ploughing) for God. If a person divides his attentions between natural and spiritual goals, he will be unsuccessful. Jesus explained, “No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to one and despise the other. You cannot serve God and wealth (earthly rewards).” (Matthew 6:24 NASB20). 

The Apostle James wrote about such a man in James 1:8. "He is a double-minded man, unstable in all his ways." James again wrote, "Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded." James 4:8 (ESV)

The high calling to follow Jesus and to receive a heavenly resurrection is so wonderful that we should focus our whole hearts, minds, strengths, and souls on being faithful. The Apostle Paul said, "Indeed I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things, and count them as refuse, in order that I may gain Christ 9 and be found in him,… 10 that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death, 11 that if possible I may attain the resurrection from the dead. 12 Not that I have already obtained this or am already perfect; but I press on to make it my own, because Christ Jesus has made me his own. 13 Brethren, I do not consider that I have made it my own; but one thing I do, forgetting what lies behind and straining forward to what lies ahead, 14 I press on toward the goal for the prize of the upward call of God in Christ Jesus.” Philippians 3:8-14 (RSV)

Therefore, brethren, be the more zealous to confirm your call and election, for if you do this you will never fall;” 2 Peter 1:10 (RSV)