Is there a DIFFERENCE between Matt 28:19 and Mark 16:15-18 ???

"What shall we say then that Abraham our father, as pertaining to the flesh, hath found? For if Abraham were justified by works, he hath whereof to glory; but not before God. For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. (...) How was it then reckoned? when he was in circumcision, or in uncircumcision? Not in circumcision, but in uncircumcision. And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed unto them also:" Romans 4:1-3; 10-11.

"Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also: Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith." (Romans 3:29-30)

"For circumcision verily profiteth, if thou keep the law: but if thou be a breaker of the law, thy circumcision is made uncircumcision. Therefore if the uncircumcision keep the righteousness of the law, shall not his uncircumcision be counted for circumcision? And shall not uncircumcision which is by nature, if it fulfil the law, judge thee, who by the letter and circumcision dost transgress the law? For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God." (Romans 2:25-29)

"Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God." (I Cor 7:19) That means, being circumcized or not represents works, and your are saved by faith, not by works lest any man should boast. (Ephesians 2:9)

"For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love." Galatians 5:6

"But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses. And the apostles and elders came together for to consider of this matter. And when there had been much disputing, Peter rose up, and said unto them, Men and brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe. And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as he did unto us; And put no difference between us and them, purifying their hearts by faith. Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?" Acts 15:5-10. By circumcision, you have to obey the law of Moses; by faith you are saved.