"Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned:" (1Tim 1:5) When the lawyers saw that Jesus couldn't be tricked by subtle arguments by the Herodians and Sadducees, they thought they'd try one last question to get him. They asked, "Master, which is the great commandment in the law?" (Matt 22:36) Jesus quickly answered in verses 37 and 38, "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment." But he doesn't stop there. He adds yet another commandment that he feels is extremely important. " And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets." (Matt 22:39-40) We cannot love our neighbor without first loving Christ with all of our heart, soul, mind, and strength. This may seem very hard and would be without his help. But he doesn't ask us to do something that is impossible, nor would he ever.
So when we read we should have charity (or love - same thing) out of a pure conscience, that is that we love Christ and others without a guilty conscience of sin, either to God or our neighbor. A renewal of Christ's love daily will greatly enhance this as the love will soon wax cold without it and to replace the love of Christ, sin will step in the door. "And because iniquity shall abound, the love of many shall wax cold." (Matt 24:12)
There is also the pure heart (actually listed first) that is to be gotten before we can adequately love Christ and others. The heart must be pure from evil thoughts. Satan will puts these evil thoughts in your heart and things will pass through your mind but like an old preacher once said, "You can't stop the birds from flying over your head, but you can keep them from building a nest in your hair." The same with evil thoughts, even those of immorality and perversion. Psalm 66: 18 says, "18 If I regard iniquity in my heart, the Lord will not hear me." Sometimes we must pray like David did in Psalm 51:10-12. "Create in me a clean heart, O God; and renew a right spirit within me. Cast me not away from thy presence; and take not thy holy spirit from me. Restore unto me the joy of thy salvation; and uphold me with thy free spirit." God can help you if you are sincere. Remember, he is for you and rooting for you if you are with him, but you and I must realize that we are his servants who can also be his friends if we obey him. "Ye are my friends, if ye do whatsoever I command you." (John 15:14) Love Him and serve Him and he'll never do you wrong.